Transcript for Investigators try to piece together who killed college student Mark Fisher: Part 2
Tonight, police are trying to figure out who murdered a 19-year-old college student. Mark fisher from New Jersey was shot dead on a Brooklyn street over the weekend. What was unusual on this particular case is that this particular homicide was in an area in that precinct that was not necessarily prone to violence. An area of Victorian homes, there was some people perhaps of privilege. Gunfire in that particular Brooklyn neighborhood wasn't an everyday occurrence. It was one of those that makes a splash here in New York. "The New York Times," "The post," "The daily news," the local TV stations, there wasn't a news organization that did not cover this murder. "The daily news" and "The post" addressed in shorthand as "The grid kid slay." That's shorthand for college football player comes to the city, ends up dead somehow in Brooklyn. Once the murder gets a nickname in the press, you know it's going to last. It's going to have staying power, and they stuck with it. For weeks, it was on the front pages. I cry and I just say "Why?" I mean it doesn't make sense to me. Why would somebody do this to him. I mean, he was such a good person. At 6:40 A.M. On Sunday, officers, answering a call about shots fired, discovered mark fisher's body along Argyle road in prospect park south. He'd been shot five times. There was a report of shots fired at that hour, and that's when the 911 calls come in. Police are called to the area and that's where fisher's body is found. He's found shot dead. He's been shot five times. Detectives came. They're knocking on doors. They're asking people for, you know, information. What did they see? What did they hear? They have to piece it together and to see who was where, what was this. I heard shots, looked out, didn't see anything. Laid back down. Heard some car doors closing, but didn't think anything of it. Some people said they heard a car screeching by, a white car. Some people said they heard a man and a woman having a conversation before the shots were fired. What's always been somewhat mysterious to me about the 911 calls is the fact that at least one of the callers very clearly stated that he heard a female voice. Witnesses that night say they heard a distinct female's voice coming from across the street. Right before they heard the five gunshots. When police check mark fisher's body, they find an atm receipt in his pocket. Just about an hour before he died, he went to a convenience store and took out 20 bucks, and at 5:25 A.M. And went back to the party. The key detail who goes to the atm with him? Antonio Russo. The wallet was missing from mark fisher's body. So that created the suspicion that it was a robbery. The 19-year-old's body was found wrapped in a blanket at the end of the driveway there at that home, Argyle road. He was laying face down, and there was something lying next to him. I think it looked like a blanket or something like that. He's still got this blanket that is under him in a way that led cops to believe that perhaps he had been rolled up in the blanket or carried out in the blanket and dumped. Mark fisher was found laying on top of what turned out to be your blanket. Yes. What do you make of that? You know, mark fisher fell asleep on the sofa, and there was a throw blanket in the back. So he covered himself with the blanket, and then in the morning when he was leaving, he took the blanket with him. The blanket found with the body came from the giuca home. That becomes a critical starting point for investigators. At some point, the police figure out that the victim was mark fisher. And they figure out that he was in this neighborhood, not where the crime scene was but blocks away at a party. So they start to make their way to John guica's house to find out what exactly happened at this party. When you found out that it was mark fisher, this guy that you'd been partying with hours before ends up dead, what was your reaction? Shocked. Kinda like, a weird feeling in your stomach. You know? Like, "Oh, wow." You got a call? I got a call from John. And what did he say? He said, "Ma, you need to come home." And I said, "Is everything okay?" And he said, "You need to come." And so you get home, frantic. What's the scene here? The press was on my lawn. Already? Yeah, and detectives were on my porch. John was a mess. He cried. He said mark fisher was a good guy, and he was devastated. In the immediate aftermath of the killing, the authorities were having trouble getting much information from people who were at this party. People weren't being particularly cooperative. When the police start asking those who may have been at this party or were alleged to have been at the party, all of a sudden nobody knows anything. To get closure on this was extremely difficult because of the lack of cooperation and indeed intimidation on the part of some of the people involved in this. It was very frustrating early on, I think because we were unaccustomed to seeing that kind of coordinated coverup. What we ran into was in the first 48 hours was a -- locating people who made themselves scarce, and then when we did find them, finding out that they had no intention of helping us to begin with. Instead of trying to do everything they could to help solve the murder of mark fisher, they lawyer up and thumb their noses at the police. It's a little bit shocking. It's sickening to me. I don't know how people could live with their consciences. They spent an entire night with this person who's now dead, riddled with bullets, and the first thing they're going to do is lawyer up? The pressure that was put on my family was horrendous. It was very frustrating for police, for prosecutors in the Brooklyn da's office. They don't like to be stumped. .
This transcript has been automatically generated and may not be 100% accurate.