valerie castro tells us the good news. >> reporter: as hurricane milton barrelled towards florida iny, buddy. >> reporter: a florida highway patrol trooper rescuing the bull terrier from chest-high floodwaters. the dog ended up in the care of the leon county humane society, naming him trooper. >> i was, like, he's with us, and we get to decide what happens with him, and we get to make sure that he's going to have a happy life and happy ending. >> reporter: the shelter says in the first week more than 500 inquiries were made from people hoping to give trooper that happy ending and a new home. but one in particular stood out above the rest. >> they sent an e-mail to us within the first week of us having him before we were even, like, accepting applications on him or thinking about getting him adopted out. >> reporter: the e-mail came from frank and carla spina, dog lovers familiar with the breed, who had also recently said good-bye to their own beloved bull terrier diesel. >> diesel left a hole in our hearts the size of a baseball. and we were really sick over it. and, when we, i think

nbc's valerie castro is joining us from huntington, pennsylvania, where mangione is behind bars.ain john monaghan author of "nypd takes boston" and national correspondent for "the new york times" amy chen. great to have all you here. valerie, walk us through the latest evidence. >> reporter: good to be with you, ana. it appears several key pieces of evidence are coming together in terms of the investigation. the nypd announcing yesterday that the gun that mangione was found to be carrying at the time of his arrest in altoona, pennsylvania, is a ballistics match to the shell casings recovered from the scene f the shooting in manhattan. the nypd mentioning fingerprints. last week the nypd released surveillance images of the person of interest. they were images taken from a starbucks the day of the shooting close to the scene. police recovered a discarded water bottle and protein bar wrappers from that starbucks. they say fingerprints on those discarded items are a match to luigi mangione. finally, two senior law enforcement sources tell nbc news that a notebook that luigi mangione

nbc's valerie castro is reporting from huntington, pennsylvania. t new details are we learning, valerie? >> reporter: chris, we're starting to learn more details about what police believe was the path that mangione allegedly took after the shooting that took place last week. they believe after riding a bike into and out of central park and then taking a taxi cab to upper manhattan near the george washington bridge area where there is a bus terminal, rather than leaving the city at that point, police now say they believe he jumps on a subway train and headed back downtown toward penn station and left the city from that point, making his way into pennsylvania. they say he stopped in philadelphia and pittsburgh, as far west as pittsburgh, before heading back east to altoona where he was arrested on monday. we're learning more about the fight to potentially bring him to new york to face charges there. we know he is still currently being held here in pennsylvania in the detention center behind me. but the district attorney in manhattan spoke briefly a sh

nbc's valerie castro is in pennsylvania where mangione remains in custody. with us former fbi supervisor rob it d'amico and retired nypd officer jillien snyder, adjunct lecture at the john jay college of criminal justice. valerie, let's start with new details about mangione allegedly doubling back to evade capture. what more are we learning about that timeline? >> reporter: hi, anna, good to be with you. even though mangione is in custody, police continue their investigation and they continue to review surveillance video from the day of the shooting. they now say that they believe mangione rode a bicycle into and out of central park and then took a cab up town to the george washington bridge area. that's where they say that he appears to have boarded a subway train and headed back downtown towards penn station and from there is where he made his way into pennsylvania. they say he stopped in philadelphia and made his way as far west as pittsburgh before then heading back east and ending up in altoona where he was arrested earlier this week. >> and valerie, ma

joining us now, nbc's valerie castro, outsides prison where the suspect is being held in pennsylvaniaalter, a retired nypd professor, and now a law professor. valerie, what does this petition say, and what else are we learning this morning? >> reporter: good to be with you, jose, that petition is for a writ of habeas corpus, essentially it seems as though his defense attorney is arguing that he's been unlawfully detained or imprisoned illegally, saying there is not enough evidence to continue holding mangione here in pennsylvania, arguing that he should have been given some sort of bail. he is currently being held without bail, and his attorney indicated that he was not very happy with that decision by the judge. so this will potentially lead to some sort of court hearing, although that hasn't been scheduled just yet. the nypd announcing yesterday that they do believe there is enough evidence in this case linking mangione to the scene of the crime. they say the gun that he was found to have been carrying when he was arrested in altoona, pennsylvania, matches shell casings that were fo

joining us now, nbc news correspondent valerie castro, following all of these breaking developments. rie, what other details did we get from police here? >> so you heard the police chief mention that finding a motive is the top priority. he mentioned there are a couple of factors that appear to have come into play. one thing he wants to caution is there is a document circumstance circulating on social media that's been described as a manifesto. police say that's not been verified and caution if anyone is seeing that, they're still trying that verify that document and authenticate it. he's mentioned that people report bullying may have played a factor in this case, so they're investigating that as well. also trying to figure out who was close to the suspected shooter, who were her friends, who did she interact with in the most recent months, who would speak to her frame of mind. they're asking for anyone like that in the school community to come forward. as for the patients who were hospitalized, there were six, we know two were listed as having life-threatening injuries. the police ch

valerie castro joins us now. valerie, for most of us, this is abhorrent. can you describe what's for sale and how are retailers reacting? >> reporter: most of the merchandise that we have en have been around the words deny, defend and depose. those were on the shell casings found at the scene. as you mentioned, t-shirts, mugs, bumper stickers, have all been emblazoned with those words. etsy earlier this afternoon and i found a sweatshirt and ornaments and friendship bracelets. those beaded bracelets, those were being sold. most of the online retailers, they prohibit items that glorify violence. ebay did issue a statement around this exact issue saying -- we did reach out to other retailers. they have not gotten back to us. >> valerie, beyond merchandise, there's a lot of chatter in the comment sections online. people seemingly celebrating the murder of this ceo. how concerned is law enforcement about this discourse and behavior? >> reporter: the biggest concern from law enforcement is any copycat violence. actually just today, the altoona police department

valerie castro is following this story for us. what's the latest, valerie? >> well, chris, the latest headline we received from the nypd is that the gun potentially used in the killing has been tied to a gun mangione was found carrying on him at the time of his arrest in altoona, pennsylvania. the commissioner speaking within the last hour about the connection made. she also touched on fingerprints found here the scene on evidence also seem to match those of mangione. take a listen to what she said a short time ago. >> we got the gun in question back from pennsylvania. it's now at the nypd crime lab. we were able to match that gun to the three shell casings that we found in midtown at the scene of the homicide. we're also able to, at our crime lab, to match the person of interest's fingerprints with fingerprints that we found on both the water bottle and the kind bar near the scene of the homicide. >> you'll recall last week when police were still searching for the suspect, they released surveillance video of the person of interest at a starbucks near the cr

valerie castro has the story for us. what more can you tell us? >> reporter: chris, we are awaiting a press conference from law enforcement officials in about 15 minutes to update us with more information. what we can tell you so far is that we know there are two victims in this case. a teenage student as well as a teacher. six others were also injured and transported to a local hospital. we are told two of the injured are suffering from life- threatening injuries. what is the most rare in this case and perhaps standing out the most is that police say the shooter in this incident was a 15-year- old female student which we know is incredibly rare. it is a nonprofit that advocates for tougher gun laws. they say in the last decade, out of more than 500 school shootings, less than 5% have been female shooters. we know that investigators are speaking to the teenage girl's parents. we are told they have been interviewing them since yesterday and that they are fully cooperating. police of course are looking to see if there were any red flags or signs tha

joining us now is valley castro in huntington, pennsylvania, and mark claxton, a retired nypd detective, director at the black law enforcement alliance. valerie, what's the latest this morning? >> reporter: jose, good to be with you. police continue their investigation, even though he's in custody. they are looking into his movements, his whereabouts following the shooting in manhattan. police say they believe that after he made his way uptown near the george washington bridge where there is a bus terminal, instead of leaving the city at that point, he appears to have gotten back on a subway train and headed downtown towards penn station. from that point is where they believe he made his way into pennsylvania, hitting cities like philadelphia and as far west as pittsburgh, before heading back east where he ended up in altoona, pennsylvania, and of course, was arrested earlier this week. as far as his travels within pennsylvania, police are still trying to figure out exactly what mode of transportation he used to get between those various cities. jose? >> mark, we now know -- we were just hearing about the movements after the shooting and what