it's my last. >> it's just you the have to look for truth and justice. >> you never give up the fight.

>> the truck was left, windows partially down, keys in the ignition, i believe some of melvin's belongings were low still located in the truck. other than that the truck was in fine condition, except for some marks in the back of the bed pick-up truck.

>> and the truck radio was tuned to a rock music statement. just a year earlier, melvin had an affair with a woman name teresa hartman. melvin and teresa left their life behind and fled to montana. melvin's wife joanne and teresa's husband ron took the time to get better acquainted too. >> mrs. hartman and mr. snyder struck up a relationship and were intimate with one another. but after only three weeks, melvin and teresa decided they had made a mistake and moved back home. >> yes men, change partners

across from where you are. change partners and swing her. however in this rent disappearance, neither teresa and the bank reported no activity on any of melvin's credit cards. >> he had a young son, he was early 20s, and this wasn't the kind of man that would run off and leave family obligations. >> which is why investigators began to suspect foul play. narrator: this is the storm sea captain: there's a storm comin narrator: that whipped through the turbine which poured... surplus energy into the plant

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43-year-old melvin snyder, a gentleman farmer and factory worker, went missing. his family knew of no reason he would have left home. >> he would virtually have to live in a cave and have no contact with outside world not to have some sort of record with something.

>> we had divers check the ponds in the area. talked to neighbors, if they had seen anything unusual, if they saw him leave. no one did. >> melvin's dental records were compared to every unidentified body discovered anywhere in the united states, with no success. the only lead in the case was from a neighbor who said he saw a brown pickup truck near melvin's home on the day he disappeared. it was similar to the truck that ron harshman owned. ron's wife and melvin snyder once had an affair. >> whether it was harshman's truck or not, i don't know. we don't know. >> police discovered that harshman had purchased a .25-caliber handgun just a few weeks before melvin's disappearance. coincidentally, a .25 caliber

shell casing was discovered in melvin's barn on the day he disappeared. police searched harshman's home and found ammunition for a .25-caliber weapon, but no gun. >> i asked him where the gun was and he said, you will have to ask teresa. she is the one who took the gun, she liked it and she took it. so when we asked her, she said no, it's a lie, i don't even like guns. i don't know anything about the gun. >> during their investigation, police also learned that ron harshman and melvin snyder once had an unpleasant confrontation over the affair that melvin was having with ron's wife. >> he learned that mr. snyder was coming to his home to pick up his wife and he crashed his car into him. >> he had a gun with him at that point, shot at him.

did not hit him. nothing happened. no one was hurt. >> melvin didn't want to pursue the matter, and no charges were filed. >> melvin had expressed a great deal of embarrassment about the whole incident and i think he sort of felt it was, in part, his own fault that it happened. >> and this was one more interesting twist in the case. melvin and joanne snyder had come to terms with the affair, but the harshmans had not. >> melvin was trying very hard to make the marriage work. mr. and mrs. harshman on the other hand had a rockier road. although they did attempt to patch things up, eventually in the following spring they separated and teresa filed for divorce. >> joanne snyder denied any involvement in her husband's disappearance, but she admitted having several telephone conversations with ron harshman

the week before melvin disappeared. both joanne and ron insisted the calls were innocent, and that's where things stood. one year later, ron and teresa harshman divorced, sold the farm, and ron moved out of the area. he continued to say he had nothing to do with melvin's disappearance. and he even demanded a meeting with police to stop what he called their harassment. >> we did have the meeting. we had lunch together. it was -- he was sociable, but he bordered on being angry. and the whole purpose was for me to stop interfering in his life, both his social life and with his coworkers. i explained to him that i was an investigator and that all he had to do was to take a polygraph test and i would personally

apologize to everyone, including his co-workers. >> but that was an offer he didn't care to accept. we had no body, we had no actual gun. we knew what the past history was between ron harshman and melvin snyder, and common sense

we had no body, we had no actual gun. we knew what the past history was between ron harshman and melvin snyder, and common sense will tell you, yeah, he has good reason to want to kill melvin snyder. he is the only person that we know of that ever wanted to harm melvin. but that doesn't prove it in a court of law. >> before his disappearance, melvin snyder told friends that he was afraid of ron harshman because ron was still angry about the affair he had with his wife. >> always have a strange feeling about the fact that he, in essence, had predicted something like this was going to happen. >> for the next 15 years, the case haunted prosecutor jack nelson. he knew melvin snyder personally. and something just didn't add up.

a .25-caliber shell casing was discovered in melvin's barn, and ron harshman purchased a .25-caliber handgun just a few weeks before melvin disappeared. but ron was never able to produce the weapon, saying it had been misplaced. >> there was a lot of information there, but nothing new was coming in to give you the opportunity to do anything more with it. >> nelson pored over the case file and discovered an interesting notation. ron harshman admitted test firing his new .25-caliber pistol in his backyard just after buying it. that gave nelson an idea. >> what about going out there and seeing if we can find a shell casing and then compare that to the one in the barn. >> when mr. nelson originally

told me that and i just kind of gave him a look, this was 15 years to try to find a shell casing in grass, and we are not sure of the exact area. but in this case, being the fact that it's murder, i'm willing to try any idea and it was worth a shot to do. >> police found help in nearby gettysburg, pennsylvania. don hinks known in these parts as a retailer who sells metal detector equipment. these metal detectors were often used to unearth military artifacts. >> i went out and found three french and indian war cannon balls and one whole on the braddock campaign, that probably gave me a bigger high than this .25-caliber shell casing. >> but hinks and several colleagues were happy to do what they could, despite the fact that harshman farm was several hundred acres.

>> but there was so much trash out there, so much farm equipment, this is the place where they would throw the garbage along with the tin foil and toothpaste tubes and all the junk went out there. so the challenge was working through 130 years of trash and picking up the single .25-caliber automatic shell casing that we were looking for. >> modern metal detectors use computer processors to measure levels of conductivity. which enables them to identify the type of metal and the depth of the object underground. >> they are basically computers that can pretty well tell you what happens down there how deep it is. it does everything but dig for you today. >> hinks and his team found many shell casings, but none that were .25-caliber. then hinks got a signal near a

clothesline post. >> in about 20 minutes, i got a signal that was in the proper reading range as far as the detector was concerned for a shell casing. i went down, got a plug, turned it over and sitting in the plug was a .25 caliber shell casing stuck to the bottom. when you look at it, and you see the patina on it, you know, it's not a freshly buried object. >> my first thought was this is too good to be true, this cannot be the one that he actually fired. >> investigators hoped that after 15 years in the ground, the shell could still be tested. it doesn't operate out of basements or back alleys. it grows more sophisticated every day. if it were a business, it would be a fortune 500 company.

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15 years after melvin snyder's disappearance, investigators found a .25 caliber shell casing several inches beneath the soil on ron harshman's farm. it was the same caliber and made by the same manufacturer as the shell casing found in melvin's barn. when someone pulls the trigger of a gun, there's a mini explosion inside. the bullet goes through the barrel. the shell casing is forced backwards, coming in contact with the breech face before it is ejected. the breech face in any gun has

unique and distinctive marks from the manufacturing process. >> it's subjected to several milling and finishing processes, which cause small, microscopic imperfections to be imparted to the surface. >> and those same marks are imprinted on each and every shell casing that exits that gun. ballistics experts at the pennsylvania state police crime lab were asked to analyze both shell casings. >> when he first got the casing, he said, you know, this is somewhat corroded and it has been exposed for a long period of time. he said, don't get your hopes up. >> i'm not a soil expert, it could have the effect of minimizing any distortion or variation that could have occurred had it been on the surface on the ground and maybe been exposed to rain, corrosion, other things like that. being under the ground may have in this particular case helped to maintain the quality of the markings that were present on

the primer. but again, it can vary from case to case. >> under a microscope, firearms examiners discovered this was precisely what happened. the impressions on the shell casing were still clear. and those impressions caused by the breech face were identical to the breech face impressions on the shell casing found in melvin snyder's barn. >> there was no doubt in my mind whatsoever that these two discharged cartridge cases had originated from the same gun. >> why would he have shot his gun on mr. snyder's property? there was no reason for that except for the fact to kill him. >> based on the ballistic evidence, prosecutors charged ronald harshman with first-degree murder. melvin snyder disappeared on may 25th, exactly one year to the day from when melvin started the affair with teresa harshman. >> mr. harshman is the kind of man that no one was going to

tell him what to do. no one was going to take his property. he became very vengeful, very angry. he was not the kind of person that was going to allow his wife to return home and try to rebuild their relationship. there was no forgive and forget. it was, i will get my revenge, and that's what he did. >> prosecutors say that the crime was premeditated. the evidence suggests that harshman drove to melvin's home, found him inside the barn and then shot and killed him with his new .25 caliber pistol. the .25 caliber round probably didn't exit melvin's body. prosecutors believe harshman drove home and returned later on his motorcycle. after he disposed of melvin's body, he put his motorcycle in the back of melvin's truck, which created the damage found in the bed of the truck. harshman then abandoned melvin's

truck 60 miles away in maryland and drove his motorcycle home. >> what did he do with the body? the body after 19 years has not been found. carefully, carefully, he must have planned where he was going to take the body. how he was going to dispose of the body. >> during police questioning, joanne snyder admitted that she told ron harshman that melvin would be home alone that day. but prosecutors had no proof that she had any prior knowledge of the murder. >> i think joanne had some involvement in this case, i am not sure whether that was done intentionally or if she was being used by ron harshman and didn't realize she was setting

melvin up. >> ron harshman pled not guilty. prosecutors knew that trying a case with only one piece of forensic evidence would be difficult. >> there aren't a whole lot of cases out there that get prosecuted without a body. there aren't a whole lot of cases that get prosecuted without a weapon. and for a case to be prosecuted with no body and no weapon was almost unthinkable. >> in july 2001, a jury convicted ron harshman of first degree murder and sentenced him to life in prison. >> he came 16 years close to getting away with this. 16 years is an awfully long time to get away with murder. he came very close. >> 15 years later, after the murder, that we went out and found that shell casing before everything caught up with him and now he is in his orange prison jacket paying for his crime.

it will catch up with you sooner or later. up next, a young aspiring singer disappears. >> a telltale sign of somebody running from something. >> she had a history of running away. she had always come back. >> surveillance cameras tell at least part of the story. >> when i saw the video, i started feeling very confident that we were focusing on the right guy. >> all they had to do now was to find him. >> 16-year-old joshan ashbrook had dreams of stardom. er