i learned that he was arrested. i was shocked. i was just so confused. i didn't think it was real. i didn't think it was possible. >> in the rarefied world of the ivy league, he was the total package. star student, gifted athlete, wildly popular. >> he is one of the nicest guys ever. >> no one could understand how a weekend visit to his parents' house -- >> you say you heard a shot? >> yes. >> ended in gunfire. >> who's already dead? >> my hub. >> charlie told the officers outside he was going to kill my mom, i had to do it. >> a brave son protecting his mom. a harrowing story, but was it true?

>> he's seated behind a desk. >> yeah, defenseless really. >> this seems to be an execution. >> was this campus hero actually a cold-hearted killer? >> the defendant sent an e-mail to his fraternity brothers called show time. >> or was the truth something completely different? >> one of the things that was always a question was, was charlie covering up for someone else? >> a trial where nothing went by the book. >> three of the jurors were crying, really hard. >> turning around in their seats, getting emotional. they see what's coming. >> he was becoming unhinged. >> i'm lester holt, and this is "dateline." here's dennis murphy with "house of secrets." >> reporter: cayuga. that's cayuga lake in ithaca, new york. and it's where you'll find one of the most competitive, most prestigious, universities in the nation. cornell. the ivy league.

big red. ♪ hail, all hail cornell >> reporter: more than 13,000 undergrads here working towards degrees will, with good fortune, take their places in medicine, the law, the arts. there's no doubt a cornell education can be a gold-plated entrance ticket to adult life. and only the best need apply. students like charlie tan. he was so kind his high school classmate featured him in a video "random acts of kindness," giving gifts to complete strangers. not just a great kid, but the greatest of great kids. >> reporter: charlie was the son of chinese immigrants who became mr. everything in his high school years. scholar, athlete, class president. the guy with the cool friends. anna valentine opened up her parents' summer lake house to charlie and her other teenage pals. >> oh, he's such a nice guy. he was always happy and energetic. >> personalities, the kind of guy that comes in a room and

tells jokes? >> yeah. he's the one that, like, everybody knows him. he'll, like, walk in and, like, the room, like, lights up. he like starts telling a funny story. >> reporter: so you'd think charlie tan was another ivy league overachiever poised for take-off and great things to come. but that's not this story. this is about the charlie tan, keeper of secrets -- and quite possibly, something much worse. but before all that, charlie was as deserving a kid as ever got an ivy league acceptance letter. >> he was really, really excited when he got admitted. that was awesome. >> reporter: ivy league. >> yeah. he was so excited. he like was, yeah, super happy. >> reporter: so in the fall of 2013, charlie tan left his parents' home near rochester, new york, and drove the few hours to cornell. his exciting new chapter in a life already filled with early achievements. he pledged a frat. he wasn't big enough for cornell's varsity football team, so at 165 pounds, he was directed toward what they call the sprint football team. >> i met charlie the first day freshman year, actually. i had just gotten my locker and charlie was one of the first

people i met. >> reporter: quarterback rob pannullo. >> he's one of the most encouraging team players we have. he's a leader on the team both by example and through his words. >> reporter: rob and charlie became not just teammates but great friends. >> he's one of the most generous and selfless people i've ever met. >> reporter: charlie impressed his teammates and his coach. terry cullen coaches the lighter weight players. >> good football player, quiet, always got a smile. never late. hard worker. good kid. solid. >> reporter: go back to the handsome house in the rochester suburbs where charlie grew up in his teenage years. it's a place called pittsford, new york, and newspaper reporter jon hand knows it well. >> it's a very nice community, a very picturesque community. >> reporter: big lawns, nice cars in the garage? >> yeah, yeah. big houses, lots of new tracts. lots of executives from, you know, kodak and xerox and lawyers. >> reporter: charlie was the younger of two boys. his parents, jim and jean, born in china, lived in canada before moving charlie and his brother

to upstate new york. his dad ran a tech business that thrived. the home just radiated upper middle class comfort. his friend anna had been there, on occasions. >> i went over to his house. i didn't know his parents very well. i talked to his mom a couple times, but i didn't really have much conversation with them when we were there. >> reporter: little was known about his parents, and charlie didn't offer any details if someone asked. if he had secrets -- sorrows -- they weren't for the outside world to know about. >> he's very good at, like, keeping his emotions in. >> i have no idea what the home situation is like. i didn't know before and i don't know now. >> reporter: other than a few 911 dispatchers and a few town officers, the wider community -- the friends of charlie tan, certainly -- knew nothing about the whispers of domestic violence on placid coachside lane. >> he's a very stoic individual. it's a tough part of his life. >> reporter: the record is still sealed, but it's safe to say the tan house was known to authorities.

go back to cornell. it's the winter of 2015, and charlie is now a sophomore. on a chilly thursday morning he stopped in unexpectedly to visit his football coach. there is a softer side to this coach than drills and xs and os, and his kids know he'll always be there for them. >> our rule is, you know, if you have a problem, come on and we'll close the door. if you need somebody to talk to, we're here. >> reporter: now it was charlie who needed a shoulder. >> i said, "how're you doing?" he said, "good. but i -- i can't make weightlifting on friday." and i said, "what's the problem?" and he said, "well, i gotta go home." >> reporter: charlie seemed emotional. clearly something was eating at the student. >> i asked him if there's anything he wanted to talk about and he declined. so he just said he had to get home. >> reporter: it wasn't spring break. classes were in session, but charlie got in his car and started the drive to pittsford a hundred miles away. coach didn't know that charlie tan's life as a student at cornell would soon be over. >> you don't worry about charlie. charlie's very squared away, got

his act together, knows what he's doing. >> reporter: only charlie tan wasn't at all okay. it snowed that night, a muffling blanket covering the home where something awful was about to happen. >> why did charlie need to rush home? when we come back -- the first clue, coming from a friend's mom, who called 911. >> he didn't give us a lot of details. i'm just worried that he might do something at his house. >> and then charlie's mom makes a 911 call of her own. >> did you say you heard a shot? >> yes. >> does somebody in the house have a gun? ♪ "lean on me♪ by telekinesis ♪ ♪ ♪ mcdonald's quarter pounder with cheese

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>> reporter: when charlie tan left cornell, and made the 100-mile trip home on a thursday winter morn, his football coach knew he'd been upset. >> i asked him to call me when he got home just so i knew he was okay. >> reporter: and that very evening back in pittsford, new york, charlie spent time at an old friend's house where he seemed to his pal deeply despondent, sad, possibly depressed. not the charlie he'd known since childhood. after charlie left, the friend and his mother were so concerned they called 911. was charlie suicidal? >> he didn't give us a lot of details. i'm just worried that he might do something at his house. >> okay. >> i don't know if anything is gonna happen, but i -- i just can't take a chance. >> all right, well i'm going to have them go to -- go to that house and check on him. >> reporter: and a deputy did just that. detective steve peglow of the monroe county sheriff's office.

>> charlie told the deputy that he was just upset over some things. you know, he'd come home to talk to people. and that he was just working out some things and he would be okay. >> reporter: it was now late thursday night, almost the weekend. charlie didn't go back to school friday morning, and come monday he wasn't at practice. >> there wasn't really much i could do anyway other than text him, and he didn't respond. >> reporter: and then it was monday night something awful. >> 911 center, what is the address of the emergency? >> yes. hi. >> reporter: the caller, so distraught, confused the dispatcher. >> my name is jean tan. i just -- i heard an argument and my -- my -- my son talked to my husband. >> ma'am i can't understand anything you're saying. does anyone need an ambulance? >> reporter: it was jean tan, charlie's mother. >> did you say you heard a shot? >> yes. >> does somebody in the house have a gun? >> reporter: now the garbled story was coming into focus.

shots fired, the husband, the man of the house, was dead. >> he's already dead. >> who's already dead? >> my husband. >> your who? >> my husband. >> are you in a safe spot? >> yes, i am. >> we need you to wait outside the house for the police officer's safety. >> reporter: detective peglow was soon en route to coachside lane. he still had only a garbled account from the 911 call. who had shot whom? >> he's trying to protect me. >> your son was trying to protect you? >> yes. >> it looked like it was -- what we would call a domestic murder. it was something that had just occurred. >> reporter: on arrival, the first deputies on the scene saw a young man who would turn out to be 19-year old charlie tan standing in the driveway with his mother. >> they're outside the house? >> outside the house. it's a safety thing for the deputies. no reason to go in. let those people come out. they asked, you know, who else was in the house. >> reporter: in the next moments, the deputies heard the son tell a story that sounded

like self-defense. he had to shoot, he said, to save his mother. he'd used a shotgun. >> charlie said, "my dad's in there. he's dead. i had to do it. he was gonna hurt my mom." >> reporter: the father is shot because the boy feels his mother's in jeopardy? >> yes. >> reporter: it was getting late on a frigid february night. the deputies put the son and the mother in a patrol car. >> and they asked him where the shotgun was. there was some mention of it being in the garage. >> reporter: after securing the weapon, the deputies made their way into the home. on the second floor, in the home office, they found their victim. >> the husband, the father's behind the desk? >> he's behind the desk. the spent shotgun shells are all right there in that doorway area. >> reporter: the detective would quickly learn more about jim tan -- father, husband and businessman. >> he owned his own company. they had lived in canada and then moved to the united states some years earlier. >> successful executive, huh? >> by all accounts, yes. >> reporter: but was the

successful businessman also an abusive husband? detective peglow looked around the household as crime scene techs processed a shotgun killing upstairs. they came upon an appointment card for jean tan to appear at domestic violence court. so the working theory, justifiable homicide, made some sense. but detective peglow was no rookie. his investigation into charlie tan and what happened inside that home was just getting started. >> one of the investigators found what appeared to be newly taken passport photos, along with a list of prominent local defense attorneys. >> that's interesting. >> yes, sir. >> his story is, "i had to do it." but you're not taking that at face value, huh? >> correct. >> reporter: coming up -- a discovery on jim tan's computer triggers suspicions about his time of death. >> so how many days prior is the last email checked? >> four. that was really a big thing for me. >> reporter: when dateline continues. rning ]

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>> reporter: deputies canvassed the neighborhood but no one had heard the gunshot blasts that killed jim tan. but then, this homicide wasn't a who done it. the son had admitted moments after deputies arrived that he'd been the shooter. he had to do it, he said, to protect his mom. >> self-defense is -- is something we'll listen to. if that's what happened, then the law will -- will bear that out. so we wanted to speak to him and determine that. >> reporter: that same night charlie and his mother were taken down to the station to tell their stories. >> were you able to get a statement from the son, charlie? >> we were not. his lawyer would not let us speak to him. >> his lawyer's already on scene? >> his lawyer was on scene a few minutes after me. >> reporter: without the

cooperation of the admitted participants, the mother and the son, the detectives were on their own. it turns out a very large piece of evidence was waiting to be found, right there in their very office. a report from the house on coachside lane. >> 911 center, what's the address of your emergency? >> reporter: just two weeks before the shooting, police records show the wife placed another 911 call. >> yes, hi, my name is jean tan, and, uh, my husband just beat me up and i need your protection. >> are you injured? yes, he choked me and i'm so scared. please -- >> do you want an ambulance? >> please help. oh, he's coming. oh no. no. please come, please come. >> reporter: the dispatcher heard what sounded like an ongoing fight between husband and wife. >> hello. okay. sorry, yeah. [ unintelligible ] >> no no! no! >> yes, sorry about that. [ unintelligible ] my wife was probably upset at me. >> help me.

>> she's upset with you? >> no! no! you choked me! >> i did not. don't be childish, sorry. okay? >> reporter: a deputy was sent out to the house and noticed jean tan, the wife, was clearly rattled. reporter jon hand of rauoss cherter's democrat and chronicle newspaper. >> they found that jean was still upset. she had -- some red marks on her neck. but there wasn't enough to charge jim tan with a crime. >> so incident over. >> that night. >> he tried to kill me, but nothing results in terms of charges or makes it in -- really into the paperwork. uh-huh. correct. >> reporter: so a history of abuse, it appeared. if that were the case, charlie had told no one in his circle at cornell university. up on campus, coach cullen hadn't heard from charlie in days. and now his phone rang. >> the campus police called me up and asked me to come to his fraternity house, which i did. they wanted me to know that charlie's father had been killed. it was rugged.

we've got a bunch of players in that -- in the fraternity and everybody was obviously very upset. >> reporter: charlie tan admitting that he'd shot his father to death. >> i think it was probably disbelief more than -- and shock that this occurred. >> we had a team meeting about it. but, immediately after, there was so much support for him and everyone was amazed by the support. >> reporter: from the get-go, there was no debate, the entire frat and team had charlie's back. >> not just the sprint football team but everybody on cornell's campus that he knew well was showing support for him. everyone was always trying to help him and ask if there's anything we could do for him. >> reporter: to his friends at home, there was shock of course there too. and yet, the heartbreaking story of charlie tan protecting his mom by any means necessary made some kind of weird sense. he was, after all, the kid who was always trying hard to help. >> people talk about him being

selfless. >> yeah. >> he lives to help other people. >> yeah, he would do anything for people. >> reporter: close friend anna had a hard time wrapping her head around charlie doing anything violent. the charlie she knew was a thoughtful kid who did things no ordinary teenager did. >> my mom went through, like, cancer, and he was always there. he brought her, like, gifts and stuff. so he was always there supporting anybody. >> reporter: so, anna too would be there supporting charlie through this difficult time. a friend to the end. neither she nor anyone else could have guessed where the investigation was heading next. that the detective who'd examined the scene that night was wondering if there was more to this story. it was all obvious right away, that something was off with the working theory of the crime. a heat of passion, self-defense homicide. >> we were there for hours, obviously, searching every bit. one of the things that was noticed by one of the investigators is just, you know, the dried blood that was all over. >> reporter: dried blood? the timeline, and the whole story in fact, demanded a closer look.

>> it's certainly one of the things that starts to get your attention that, okay, hang on, there might be more. let's make sure we're -- we're on the right path here. >> reporter: and there were other observations that set their timeline back. on jim tan's desk computer where he'd apparently been working when he was killed, there were unopened e-mails going back before the weekend. >> jim is trading some e-mails with an employee. and then at some point after that, he clearly stops using his computer. he is no longer sending. he's no longer opening. >> reporter: and as detectives poked around that office monday night. >> so how many days prior is the last e-mail checked? >> four. >> four days? >> that was really a big thing for me. this was a guy that ran his own company, you know with employees and with activity. >> reporter: going back four days. that put the shooting back to that thursday night charlie came home from cornell. and a four-day-old crime scene would also explain what had been plainly obvious to the seasoned detective's nose. >> the odor of decomposition was

very strong. >> reporter: the detective now believed that emotional 911 call was bogus, a charade. >> did you say you heard a shot? >> yes. >> his mother was in peril. and he had to shoot the husband. but now you're seeing this might be days earlier. it's a "what's going on here?" thing, right? >> correct. that first inference from the 911 called and from what charlie had said in the driveway to the deputies seemed to be in, you know, in confrontation with what we were starting to see inside. >> reporter: down at the sheriff's office, jean tan, the mother, was released from custody. but not charlie. the 19-year old ivy leaguer was charged with second-degree murder. >> what did you think, anna? >> i was shocked. i was just so confused about, i didn't think it was real, i didn't think it was possible. >> reporter: charlie tan, the nice boy, the great kid, if convicted was facing 25 years to life in prison. >> coming up. store individual joe shows the

gun that killed charlie's father being purchased, but it's not charlie buying it. >> a new name altogether here. >> correct. >> and then the strange thing charlie did just before his mom placed the 911 call. >> the defendant sends an e-mail to his fraternity brothers called showtime. one freshness, under american farms, daily hand-prepared, so help us sanders. chicken... ...colonel quality guaranteed. the and i'm on a mission to prove it's the fastest. i'm betting anyone and everyone that sprint is faster than their network. and guess who's winning? the guy with a trailer full of your stuff. why overpay for wireless? switch to sprint and save 50% on most rate plans.

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>> he called me on the phone, actually, from jail. so i talked to him a couple times. >> reporter: anna didn't sit around. she was going to do whatever she could to defend her friend. because she knew, there was no way charlie did anything wrong. >> you did something remarkable, anna, and that is you sort of pulled together a whole community behind charlie. >> yeah. >> reporter: anna started a defense fund support page for

charlie. >> and it just, like, spread crazy. i had no clue what was gonna happen. >> so you just threw it out there on the net. >> yeah. i just put up the page and, like, told my friends that i did it. people i hadn't even heard of were supporting him. people from the community. everyone was doing it. >> how much money did you raise? >> around $50,000, yeah. >> why did people come out of the woodwork? >> he -- >> -- to support charlie? >> he has just been, like, one of the nicest guys ever. and i think everybody knew that and was just -- wanted to do anything they could to give back to him. charlie would, like, give everything to other people, if somebody needed anything, he would be the one to give it to them. >> reporter: reporter jon hand was working nonstop on one of the most talked about stories the county had seen in years. >> so now it's an investigation, and for you a news story. great ivy league kid blows away his father, in this nice neighborhood. what's going on in terms of response to this event? >> we were astonished. it's not very often you have a murder suspect who a bunch of people from pittsford are

rallying around. >> reporter: the case had captured the hearts and minds of a community that couldn't imagine this exceptional young man in prison. >> and these are lawyers and surgeons and political king -- i mean, these are big powerful people in new york state who were behind this kid. >> oh, yeah. >> we wish that didn't happen. but the kid deserves a break. is there some of that feeling around? >> oh, yeah. the community felt that very strongly. >> reporter: so when the trial began less than a year after the shooting, the sworn representative of the people -- with a murder case to prove -- found herself in an odd spot. >> the biggest problem was the defendant himself, because he did appear to be, you know, an upstanding nice, young man. >> reporter: monroe county district attorney sandra doorley. >> you know, from the very beginning, people were disappointed that, you know, an indictment was filed against charlie tan and that we're taking this to court. but you know what? we have to prosecute people who violate the laws of our state. >> reporter: assistant d.a. bill gargan prosecuted the case in court.

he told the jury that yes, charlie tan was a high achiever, a bright young man, who always went the extra mile for his friends. >> and perhaps he wanted to succeed as charlie tan and solve all the problems that were occurring on coach side lane. >> helping his mother, yeah. >> helping his mother. >> by killing his father. that was the solution. >> that was our theory, yes. the gun is found at the murder scene. his fingerprints are on the ammo. his mother, again, a mother saying, "my son did it," and charlie saying he had to do it. >> reporter: but did he have to do it? that was the key question. and the prosecution said no. this was no justifiable homicide. this was an execution. in fact, the weapon, the 12-gauge remington shotgun, had been purchased just for the killing, said the prosecutor. deputies found it leaning against a garbage can in the tans' garage. and when they traced it, they discovered it had just been bought from a walmart nor

cornell. >> so we sent investigators down there. and as they began to look into that, they found that the gun had been purchased by a young man named whitney knickerbocker. >> newly purchased? >> newly purchased. >> by some new name altogether here? >> correct. >> reporter: the transaction had taken place february 5th, the same day charlie left cornell. the salesman remembered the purchase. and even better the store had surveillance video of charlie's friend and fellow fraternity brother, buying the shotgun, video which was shown to the jury. whitney knickerbocker, the frat brother, was never accused of having anything to do with the killing. charlie apparently convinced him to help buy a gun. >> friends say that whitney was told by charlie that he was gonna go on a hunting trip so he asked whitney to help him. >> reporter: of course the prosecution says there was no hunting trip. charlie was planning a murder. in fact, before he got the friend to buy the weapon, surveillance footage showed how intend he was on getting one.

hours earlier, there is charlie. >> charlie tan is on video going into the walmart attempting to purchase the shotgun. he is unable to. >> why is he turned down? why can't he buy the shotgun? >> he's a canadian citizen. >> reporter: which meant there would be a waiting period. time, the prosecutor said, charlie didn't have. >> ah. so he gets a friend to come in and make the purchase. >> that was our theory, yes. >> it's hard to put together a heat of passion scenario, mom's in jeopardy, if you've purchased the weapon in advance? >> correct. >> reporter: and the prosecutor told the jury there was no evidence of a fight that evening. >> if you look at the exact moment of the killing, jim tan is just sitting -- >> he's just sitting at his desk, answering e-mail. >> answering e-mails, working to, you know, provide a living, and a pretty good living for his family. >> reporter: in fact the medical examiner testified that as jim tan sat behind his desk in his home office, he was shot three times about the chest and face. the last shot, the coup de grace. >> medical examiners still believe jim tan was alive when that was inflicted right to his

face. >> reporter: the prosecutor believes that was thursday night, the same night one of charlie's friends sent a deputy to the tan home to check on charlie's welfare. it's possible, that when the boy answered the door and said he was fine, his dad was already dead inside. but no one from the tan home called 911 that night. rather, said the prosecution, charlie and his mom grabbed their passports and fled the country. >> jean tan and charlie tan left the country, went to canada, and came back on that monday before the 911 call was placed. >> reporter: so why come back and tell a lie? the prosecution did not know. a guess -- perhaps someone had to run jim tan's business. and this last tidbit -- creepy implied the state. before that four days late 911 call was placed, charlie took the time to first send a warning e-mail to his college buddies. they would soon hear things in the news. >> the defendant sends an e-mail to his fraternity brothers

called "show time." >> "you're gonna be hearing from the law enforcement," huh? >> yes, yes. "you will be surprised. showtime." >> reporter: no, jurors. don't buy self defense, said the prosecutor in summation. this was no crime of passion. it was a planned murder. >> so this is an assassination. >> yes. >> he walks in and blows dad away. >> exactly. >> reporter: the prosecution rested. the defense team was up next. and they were about to lay out a head-spinning theory of the crime from seemingly another universe. no one saw it coming. coming up, the defense drops a bombshell. >> one of the things that was always a question of ours was, was charlie covering up for someone else? >> reporter: and then, the prosecution's stunning reaction. >> he picked up the shotgun. he moved quickly across the room. >> reporter: when dateline continues. back on everything you buy. that's 1.5% cash back on whatever these billboards are selling. what are they selling? the products not so subtly placed in this movie -

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where you'd routinely expect lots of supporters for the victim, there were none. >> there was no one who was mourning the victim. the victim's assistant from the district attorney's office -- i

sat with her the whole trial. because she had nothing to do. >> and apparently some people think that this vicious father, the victim, deserved -- got what was coming to him. >> oh, yeah. people that normally wouldn't advocate homicide -- who say, "if he did it, then he did it." and that his father deserved it. >> reporter: but the accused? his girlfriend and friends crowded outside the courtroom every morning, surrounding him protectively as he walked into court. he had all but a cheering section with pom-poms. >> i think it meant everything. i think having all the support made him, like, feel so much better, so much stronger. think he knew we were all there for him no matter what. >> reporter: his friend anna was on the witness list, so she wasn't allowed to sit inside the courtroom until the very end. >> i went as much as i could between classes for the rest of it. >> how did he seem to you? how was he putting up with it? >> some days were harder than others. some days he seemed good. >> reporter: charlie would sit in court, while his defense would build a case with evidence that seemed to support domestic violence. played that tape of jean tan calling the cops two weeks before the shooting.

>> hi, my name is jean tan, and my husband just beat me up, and i need your protection. >> are you injured? >> yes. he choked me and i'm so scared. >> reporter: defense attorney james nobles thought the 911 recording spoke volumes about that household. >> it was almost as if we were put in the hell that charlie lived in for a brief moment, and the hell that jean lived in for a brief moment. >> reporter: and they kept piling on. jim tan, continued the defense, wasn't just a bully at home. his employees testified about the abuse they, too, encountered in the workplace. >> every other person who worked with jim tan said he was miserable, says he behaved like a child, said he would bully people, said he was nasty at work. >> reporter: so a son defending his abused mother was a defense no-brainer strategy that seemed to require little assembly. the other defense lawyer, brian decarolis. >> i think most people that looked at this case said, "the

only defense is self-defense," or some hybrid of, you know, a battered child syndrome. >> reporter: but as the trial progressed, that wasn't the tack charlie's defense team planned. >> our strategy was to keep our strategic defense in our back pocket, hidden from the prosecution as long as we possibly could. >> reporter: so what was the secret defense? they were going to agree with the prosecution on one point -- that when jean called 911 to report her husband dead, the murder was days old. >> shots. i heard it. >> that call is 100% fake. there's no question about it. >> reporter: not only was the mom lying to 911 about when the murder occurred. no, argued the defense, she was lying about something much, much bigger. who the true killer was. the defense attorney saved his surprise for closing arguments. >> it was an unusual moment. because certainly i knew there were many friends and supporters

of jean tan in the courtroom, and i was going to basically suggest to these jurors that she had pulled the trigger. >> reporter: jean tan, the mom, the wife, the true killer. the defense said the shotgun was in her hand. she pulled the trigger. she solved her own problem, not her son. that was the story the defense saved for the 11th hour. >> not an easy thing to do in a packed courtroom. >> reporter: according to the defense, it was jean tan who had the motive, the motive to get rid of her bully husband, get the house, the business, the money. >> frankly, it put motive in jean tan's category more so than charlie. >> reporter: and whatever little forensic evidence was at the scene was, according to the defense, inconclusive. >> there was a fingerprint on one of the shell casings and on the box of ammunition. so what that means is that at some point in time charlie could have loaded the gun, but it still doesn't make him pull the trigger. >> reporter: as the defense saw it, the 'mom did it" theory even

explained that odd email that charlie sent his frat brothers before the 911 call -- the email called "showtime." the email implied that the story to come might not be the real one. it went on to say this -- >> "the real truth will come out one day. and you're gonna know what really happened." one of the things that was always a question and always a concern of ours was, was charlie covering up for someone else? >> reporter: in court, assistant prosecutor bill gargan appeared caught off guard and stressed when he rose to make his closing argument. >> he addressed charlie directly. he said something to the effect of, charlie, your lawyer is calling your mother a killer. he picked up the shotgun. he sort of moved quickly across the room. and he kind of approached the jury very closely with it. and, you know, he was trying to make a point. it was a very passionate point. >> reporter: brandishing the murder weapon as a prop didn't sit well with judge piampiano who told the prosecutor to calm down. >> frankly, we knew that, at that point, we had done exactly what we wanted to do. we had totally taken him by surprise. >> reporter: after a week of testimony, the case went to the jury. out in the hallway, tv cameras dogged charlie's every move.

he'd been out on bond the entire time, but his freedom could be coming to an abrupt end. >> he knows his life is hanging in the balance. that's a tough thing for anybody to go through. >> reporter: but he had the unwavering support of team charlie. they all waited with charlie as the deliberations began, then spilled over into a second day, and then another. >> every day we'd show up to court being like, "oh, is it gonna happen today?" everyone was just super nervous, like, on the edge of their seats the whole time. i knew charlie was. i knew i was. >> because if it goes in an adverse way for you and charlie, it's -- >> yeah. >> -- he's gonna be led off and you wouldn't see him for a long, long time. >> yeah. it was hard to imagine that. >> reporter: jennifer mcgoff, was a juror sitting on the case. she walked us through the arguments as they deliberated. >> i'm not sure anybody felt bad for jim tan. he made a lot of enemies in life. but everybody did recognize that that way he died, that was still a crime. >> reporter: both the prosecution and the defense had agreed that charlie's fingerprints were on the ammo. >> but did he actually pull the trigger? or did he load the gun and give

it to his mom and say "here you go"? that was the biggest point of contention. >> reporter: she was ready to vote guilty. but the panel of 12 was far from unanimous. more days passed. >> eight people guilty, four people not guilty. >> reporter: a stalemate. an impasse seemed to be at hand. but still they talked. >> three of the jurors were crying really hard. because they didn't want to think that he was guilty, but they couldn't ignore it at that point. >> reporter: the local media asked prosecutor bill gargan for updates. >> i don't have an experience of the jury being out for this long. nor do my peers. >> reporter: on day eight, after 50 hours of deliberations, the jurors told the judge they were hopelessly deadlocked. the judge declared a mistrial. >> and that didn't mean it was over for charlie by any stretch. >> no. it didn't mean it was over. it just meant that there was a long road ahead. >> charlie, a few words about how you're feeling right now? >> reporter: a long road with another trial. another set of court dates, another jury to go through the

same set of facts. unless that wasn't what was going to happen at all. >> coming up, an entire courtroom gets the shock of a lifetime. >> they're actually turning around in their seats. they're getting emotional. they see what's coming. >> as charlie tan awaits his fate, the proceedings threaten to spin out of control. >> he was becoming unhinged. ♪ raaah! when you bundle home and auto insurance through progressive, you get more than just a big discount. i gonna need you to leave. you get relentless protection. [ baseball bat cracks ] excuse me, have you seen my lipton sparkling iced tea? it's delicious fruit flavored tea with smooth, crisp bubbles. well, thanks anyway.

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charlie tan mistrial was big news in rochester. >> they could not come to a consensus regarding the murder charge against charles tan. >> reporter: everyone was talking to the media, including judge piampiano, who was running for state supreme court and spoke to our affiliate whec-tv. >> will you be presiding as judge again? >> i believe i would because the case has been assigned to me. that's the normal protocol. >> reporter: the lawyers on both sides shared thoughts about doing it all over again. >> it's a murder charge, it's not a petty larceny charge with a hung jury where you walk away from it. we recognize that the d.a.'s office isn't going to walk away

from a homicide. >> so from your perspective on a new trial how will it look differently? >> better for me. that is how it will look differently. >> reporter: unfortunately for charlie's attorneys, they'd already played their surprise defense, mom really did it. there'd be no shock value in a second trial. >> frankly, we've gotta face this like it's a brand-new case, starting today. hung juries are a situation in which you have to reinvent the wheel. >> reporter: last november just weeks after the trial ended, both sides were back in the same court, before the same judge, judge piampiano, who just two days earlier had won that state supreme court seat. it was a routine hearing to talk pretrial logistics. >> so you are expecting to set a calendar date. >> we were figuring maybe in january, a january trial date. >> jon hand who'd been there for the entire trial was in attendance too. >> there was a number of charlie's friends there myself and roughly four or five other

reporters who had covered the trial. the gang's all here, you know. and the judge said, "we have to address the motion for dismissal by the defense. it's still pending." >> reporter: that's a common motion made by most defense attorneys when they ask a judge to throw out a case, especially due to lack of evidence. >> you always do it. it's frankly, malpractice not to. >> reporter: everyone thought this would be an order of business quickly dispatched and the judge would move on to setting a new trial date. >> but then he starts talking about a lack of evidence regarding the possession of the gun and charlie ever having the gun, lack of evidence that the fingerprints were found on the shells upstairs, but that didn't skbe kate that -- indicate that he'd ever shot it. i looked at another reporter who i know and i said what's going on here? >> reporter: charlie's lawyers had a glimmer about where this was going. >> i leaned into charlie's ear. and i told him, "something good's about to happen." >> reporter: the assembled press couldn't believe where the judge was heading. >> you're holding your breath and you're going he's about to dismiss this case. the biggest case we've had in years and years and years and years. a case that jurors deliberated on for 50 hours, a second-degree murder case. >> reporter: assistant prosecutor bill gargan saw the train wreck ahead and wasn't at

all pleased. he grabbed the mike. >> can i speak? and the judge very quickly said, "no, you may not." bill gargan continued to speak, the judge said i'll pet you in handcuffs. >> the judge to the district attorney. >> yeah. never seen that before. "yeah, i'll put you in handcuffs." >> you're out of line here. >> and a court deputy walks up behind bill gargan, the prosecutor, not the defendant. >> he was interrupting. he was becoming unhinged. >> after the dramatics with the prosecutor, the judge did finish his thought. he threw out the entire case against charlie tan. a judicial ruling that meant the case couldn't be re-prosecuted or retried. >> it was a big win for charlie tan. he was ecstatic. >> reporter: outside the courtroom, the media was waiting for charlie, the former defendant, who hadn't yet spoken to reporters. >> charlie! c'mon, now you'll talk to us, right? >> back up, please, please, please, calm down. >> and before we got a chance to him, his defense lawyer ushered

him out, down a hallway. >> what did you think? i mean did you take it all in? i'm not sure how he took it all in. >> i'm not sure i took it all in at first, yeah. >> that this is over. >> yeah. >> it's done. >> reporter: not quite everyone. assistant d.a. bill gargan was fuming. >> were you willing to get arrested? >> absolutely. i was more than willing to have handcuffs placed on me to argue my point because i did not cross any lines. >> what recourse do you have? >> there is no appeal. that i know of. >> so charlie tan is free. >> that's it. there's no appeal as of this order of dismissal because there had not been a verdict by the jury. >> the event didn't happen. >> correct. >> reporter: so in the people vs. charlie tan, you had to cynically wonder whether the son's vocal supporters carried the day from outside the courtroom. >> so you're talking about the division in the community. i guess some of them think the golden ivy league boy was able to kill his father and get away with it. >> yeah, there's a question of,

you know, what does afluchbs fl buy you in a courtroom. >> strange story, the whole thing. >> yeah. >> reporter: charlie's mother, according to the district attorney, will not be prosecuted, there has never been any evidence to show she is responsible for the murder. >> could it have been the mother? >> you know, i look at a 12-gauge shotgun. she was a small woman. i don't know if she was capable of even being able to discharge that kind of weapon. >> reporter: so the only two people who know what happened in that house, charlie and his mother, have stayed mum all this time. neither was ever interviewed by police. neither has spoken publicly about a case now closed, but far from resolved. >> people will say that this is a kid who killed his father and got off. and people will also say, no, it isn't, they couldn't prove it. you've got two groups of people back there who said i don't care what happened. i'm never sending this 19-year-old cornell student to prison. >> the mom and brother are running the company jim tan started. as for charlie? >> is he okay, you think? >> yeah, he seems okay. he's very positive. wants to get back to school. >> he's a great kid who's a smart student and a very popular

kid who's done well and succeeded in all elements he's been in and it's time to move on now. we all welcome him back with open arms. >> reporter: but that didn't happen. the university let charlie know if he attempted to return to cornell, it was prepared to discipline him for violating the school's code of conduct. so charlie withdrew and with that action lost the cornell version of the gold-plated entrance ticket to adult life. his former coach thinks charlie will, regardless, find a way to succeed. >> if he can get over the turmoil that he came out of, i think he'll do fine. he's got everything going for him. >> reporter: in his young life he'd pleased everybody. his coaches, his teachers, his devoted friends. outwardly happy. inwardly? who really knew. all one can say with any certainty are the known facts of a murky case. he got a friend to buy him a shotgun, said goodbye to the ivy league, and on a winter's day drove home.

>> that's all for now. i'm lester holt. thanks for joining us. oc: "headn runs :02 ===take vo=== oc: "heads up. explosion runs :02 ===take vo=== right now at 11: may day rallies turn violent in seattle tonight. how it spiralled out of control. heads up! >> receiight now at 11:00, mayd rallies turn violent in seattle. plus a look at more peaceful protests in the bay area. then a bay area man killed while out on a flight with a tourism company. and prepare for a possible traffic nightmare in the east bay. the one closure that could cause a huge slow down. good evening, everyone, i'm terry mcsweeney. peggy bunker is off tonight. a popular road that helps drivers in the east bay