Now, we begin with a murder mystery. A well-known horse trainer gunned down in his home. The equestrian world reeling over his death. Abc's linsey davis has more on this. Reporter: Long island police... See More
Now, we begin with a murder mystery. A well-known horse trainer gunned down in his home. The equestrian world reeling over his death. Abc's linsey davis has more on this. Reporter: Long island police are searching for a killer this morning. And while the they're remaining tight-lipped about what they may know about the person who shot a popular equestrian in the chest, there are reports the shooter may have known the victim well. This morning, a mystery and a manhunt, after a renowned horse riding instructor was fatally shot, as he sat on the couch in his long island, new york, home. We heard like six gunshots, which you do not hear around here. Reporter: Police say ross risener was sitting with his long-time partner in his living room, when an apparent sniper fired multiple bullets through the window of the victim's suburban home. Killing risner and grazing his partner of 26 years in the arm. It was so frightening, it was so loud. Came running to the front of the house and there were a million police cars and ambulances. Reporter: Risner seen here in this youtube video, trained star riders for decades. His brother said he was at the top of his profession and was expected to take a riding team to the u.S. Equestrian federation finals in new jersey next month. Police say he was targeted. But have not said why. This is not a random act, given the information that we possess. I believe they were fired on by someone who was intentionally firing at them. Reporter: His brother, too scared to show his face, told abc news, there was some bad blood between his 50-year-old brother and an old friend with whom he had a dispute. There seemed to be some falling out. It's speculated that he may be the closer catalyst of this tragic ending of my brother's life. Reporter: He describes his brother as a wonderful man, always the life of the party. Ross was in the height of his career. Was excelling. Sadly, that opportunity has been taken away from him. And the gunman reportedly stood in the couple's yard and waited for the men to appear in the living room before shooting. The suspect is believed to have fled on foot. Police do not have a suspect in custody and have not made any arrests. Going to bring in dan abrams. We heard from authorities saying, they realize this was not a random act. The first thing they want to do is reassure the community to say, everyone else doesn't have to worry here. This was not a random killing. And if you look at what happened here, you're talking about multiple shots through a window, in a suburban area. This was clearly a targeted shooting. How do police move forward with the investigation? It seems they have someone they want to rule out, right? These days, they never want to call anybody a suspect until they're ready to arrest them. There's no question they want to talk to this person who apparently used to live in the house with them. Someone who may have had a beef with them in the past. There's one report that this person may have been charged with harassment. That's the person they want to talk to first, to rule him out. Right? So, they can talk to this person and say, there's no way he was there. He's got an alibi. They begin the rest of their investigation. This is so shocking. And thinking of his long-time partner and his family right
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