Transcript for Tito Jackson's ex-wife Dee Dee Jackson tragically drowns: Part 2
Reporter: It's 3:30 am on that hot August night in los Angeles. At Dee Dee Jackson's home in the San Fernando valley, a ringing phone wakens the sleeping household. I got a phone call and I was told that my mom had been in an accident and that I need to go to the hospital right away. Reporter: Paramedics had rushed an unresponsive Dee Dee to the hospital after an apparent swimming accident at the home of her new boyfriend don bohana. But before the boys can reach the hospital, doctors pronounce their mother dead. When he said, "She's dead," I don't remember anything else he said. Reporter: The next phone call is to their dad. It was just horrifying and just, the coldest day of our lives. Here by the bushes is where Dee Dee Jackson was found. Reporter: To unravel what happened in that pool is the job of detective Bob snapper of the la county sheriff's department. This pool is approximately 15 feet deep. Evidence of heavy drinking is all around. I found a 1.75 liter bottle of uh rum that was empty. And also two quarts of wine. They were both empty. Reporter: In fact, snapper can smell liquor on bohana's breath. He had actually blurted out the wrong address when he called 911. 644 -- Reporter: And is still drunk hours after paramedics first arrived. I did do a test on Mr. Bohana to see how severely drunk he was. He pretty much failed the test. Reporter: Despite bohana's impaired condition, snapper asks him for a detailed account of just how Dee Dee has drowned at this very pool. She came over and swam over to him and then go down and touch the pool light. And then do an olympic-style turn to go back to where the spa was. He then got out of the pool, and then all of a sudden he noticed that she was down in the deep end of the pool, and it seemed that she was in trouble. He jumped into the pool and then he said that she fought him off. He got out of the pool and used the pool pole and extended that out to Dee Dee in the water, and she would not grab onto it. He goes in and lifts Dee Dee up from under her arms. And gets her out of the pool in the deep end. Reporter: But it is too late. Snapper says bohana relates the traumatic incident in a precise, matter of fact manner. Was his demeanor suspicious to you in any way? No, not really. No. Reporter: But nothing stood out to you that said, "Wait, this is no accident?" True. Reporter: Word of an accidental death in a family considered Hollywood royalty makes big news in L.A. Janet Jackson and four of her famous brothers attended the funeral -- Reporter: Like any Jackson tragedy, Dee Dee's burial is akin to a state funeral. Former parents-in-law Joe and Katherine are seen, and there's ex-husband Tito. The biggest family superstar avoids the crowds. Instead, supporting his grieving nephews in private. I remember our uncle Michael flew in town and swept us away. He wanted to protect us from going into some type of terrible depression. Reporter: But festering beneath the pain lurks suspicion and doubt about don bohana's story. Family and friends say it doesn't add up for one critical reason. Dee Dee is terrified of the water and cannot swim. My first question was, drown? What was she doing in the water? Dee Dee and I, neither of us swam. And to hear stories that she was doing these olympic turns, it just doesn't make sense. Doesn't add up. Reporter: Suspicious, so all await the coroner's report, hoping for answers. The autopsy is conducted by an L.A. County coroner, Dr. David posey, a central figure in this drama. But posey's autopsy report adds more questions than answers. With disturbing details, Dee Dee's blood alcohol level is shockingly high. Three times the legal limit for driving. But even more alarming, posey notes there are numerous bruises and scrapes on Dee Dee's face and body that he describes as the result of "Blunt force trauma." Also lacerations on her lips, tongue and earlobe. Posey raises the specter of foul play, using the words "Assisted drowning" and labeling the marks on her body "Non-accidental." Just the evidence alone of all my mom's injuries is enough for me to know he -- he killed my mom. Reporter: But despite those seemingly suspicious markings on Dee Dee's body, the coroner posey rules the manner of death "Undetermined." And it stays that way for two years with little action from the district attorney.
This transcript has been automatically generated and may not be 100% accurate.