pay for sending him, taking years out of his life. reporter: when they took a closer look at christopher s more recent history. they could easily see his improved behavior wasn t exactly lasting. even girlfriend juliette s influence couldn t keep christopher from slipping up. yes he went back to college after he returned from samoa, but soon dropped out. he did form a company. but the company folded. he didn t seem to be motivated. reporter: yeah. we fried to get him to stay in jobs. nothing seemed to be working. reporter: what john sutton didn t know was that his son had gone back to the one job he seemed to be good at selling drugs. nor did he know that christopher s friend, garrett kopp was one of his best clients. kopp it turned out had been buying and sometimes reselling the drugs, mostly marijuana and xanax. and he and christopher spent plenty of time sampling the goods according to the prosecutor kathleen hogue.
reporter: miami homicide detectives larry bellevue and art manney had a problem they were afraid the man who shot sutton was a frequent visitor at the sutton home. and they at least suspected the sutton s own son, now john s care giver was all mixed up in it somehow. i was becoming more concerned. reporter: was john sutton a sitting duck for another attack one that might finish him off. you must have found it a little worrisome that john sutton was actually living with his son christopher and being cared for by christopher. sure. reporter: still they worried but did not act. even though they knew full well that garrett kopp, the shooter they were sure, was still hanging around. isn t that right that kopp was there? absolutely. again we still didn t want to tip our hand. reporter: should christopher have been a suspect at all. after all does this sound like the behavior of guilty men.
so, now the complexion of the investigation changed. trying to think why would garrett kopp do this? i mean he is like 20-year-old kid. obviously there is a tie with christopher sutton and him. reporter: as for christopher himself, the detectives had no trouble finding people with an opinion about him. the cops should be looking at christopher sutton. because of the lengthy family history of problems that john and susan had had with their son christopher who was a handful from a very early age. reporter: a very early age, actually. as john sutton recalled all too clearly. did he get into fights at school? i can remember that happening early on in preschool. reporter: it got worse as christopher got older. did he get into trouble? absolutely. there was vandalism, not only of our own things.
and three months after the august shootings when john decided he was ready to go home to the house in which the shooting happened, christopher went with him. eyes for his blind father. and at that point he was more involved in driving me around or some care giving. reporter: but now it was almost christmas. still no arrests. the detectives were certainly following up leads trying to find anyone with a motive to kill the suttons. oh, understand the digging they were doing was mostly in mounds of dry paperwork. records of phone calls and the like. and then, somewhere in the middle of that pile, there it was. and boy was it a doosie. he is sitting across from me and i look at him. i go, al we got something here. reporter: a phone call from a killer when dateline continues.
when i got the phone call and said there was a murder/suicide down in coral gables. we heard that the husband was en route to the trauma center. and in critical condition. reporter: en route with two bullet wounds to his head. had sutton killed his wife and turned the gun on himself. no, that theory was quickly dismissed when the paramedic put out a report. he can t provide any info. he had wounds to his hands which would make it clear like it was defense type wounds that somebody else must have shot him. he put his hands up. reporter: obviously. first clue. this is not murder/suicide. reporter: who or why would anyone want to harm john or susan sutton? the suttons had lived exemplarily lives, seemed to have it all. a beautiful house with a 31-foot boat out back. in exclusive coral gables, the