And while Thai authorities have ruled the actor's death as a sex play accident -- auto-erotic asphyxia gone wrong -- some say the evidence just doesn't add up.
"The thing that I am really questioning is, how was he bound, and how was he able to tie his own hands?" said Robert Dunlap, who interviewed hundreds of people who practice deviant sex behaviors for his 2002 documentary film, "Beyond Vanilla: An Unforgettable Journey Into the Wilder Side of Sex."
"This doesn't look like a solo act at all," he told ABCNews.com. "In order to have an orgasm, his hands would have had to be free. There is something very peculiar about this."
"You don't dress just for yourself," he said of the photos that revealed women's clothing. "Usually there is some sort of show and someone else is involved. It probably went horribly bad and they left."
Carradine's manager Chuck Binder has publicly echoed his own concerns.
"How do you get a rope around your neck and around your genitals and do all this by yourself?" Binder asked. "My take is there was definitely foul play. There's a lot of weird stuff that happens in Bangkok. This isn't L.A. or New York."
With funeral plans still on hold, the family hired Baden, a renowned New York forensic expert, who flew to Los Angeles Monday to conduct a new investigation. Funeral plans have yet to be announced.
"If this act was for pleasure, I can tell from the ligature," Baden told columnist Cindy Adams. "Some cloth would've hidden the rope mark around his neck so that it wouldn't show next day. I'll have to see the photos before they cut him down."
Mark Geragos, attorney for the actor's half-brother, Keith Carradine, even suggested on last week's "Larry King Live" that a Kung Fu secret society could be to blame.
But Carradine's fourth wife, Marina Anderson, told the New York Post, "If he was involved in secret societies, it was a secret that even I didn't know about. But he did have some big secrets."
Those secrets, according to at least two of Carradine's four ex-wives, included a passion for deadly sex play.
His third wife, Gail Jensen, told RadarOnline that he liked to tie himself up, had a fetish for Speedos and often experimented with nearly drowning himself in the pool.
In another interview with TMZ, Jensen says that Carradine had hung himself up in the basement in a crucifix position, mimicking Jesus Christ, while a party was going on upstairs.
"David was pretty strange," she said. "He would like to get tied up. He would tie himself up and I would walk in and see him and say, 'Oh, my God, David, you got to be kidding me -- and I would (turn around and) walk out. I would leave him to his own devices."
Jensen, who was divorced from Carradine in 1997, added, "He liked to be tied up. And he could tie himself up ... He spent days planning a different feature. He would go to a hardware store and buy the stuff."
"It was never sexual," she said, noting that Carradine liked bondage but never choked himself.
Anderson, his fourth wife, told ABCNews.com that her claims in her 2003 divorce papers that he practiced "deviant" and "dangerous" sex behavior, including incest, were true.
Carradine was married five times and has five daughters and two sons.
But according to Dr. Martin Kafka, clinical associate professor of psychiatry at McLean Hospital in Belmont, Mass., all that has been reported on Carradine's body is consistent with auto-erotic asphyxia.