The Omidi brothers came under fresh scrutiny when Paula Rojeski became the fifth person in the past three years to die after 1-800-Get-Thin Lap-Band surgery. Her death, in September 2011, attracted the attention of Los Angeles homicide detectives.
Rojeski's friends say she wanted to lose weight for an upcoming birthday.
Recalled friend Marni Rader, "She said, 'Oh, I want to get this surgery.' And I said, you know, 'Why Paula, you don't need it. You look great, you are fine.' [She said,] 'No, no, I want to be skinny, I want to be skinny.' "
Paula died on the operating table, and the circumstances of how that happened -- and whether she could have been saved – have now led LAPD homicide detectives to investigate whether a crime was committed.
Lawyers for some of the other families suing the Omidis say they also have been contacted for more information by a number of law enforcement agencies.
"This place seems to be a magnet for bad outcomes," said Alex Robertson, an attorney for the families. "Ultimately, justice may be for these families that if laws have been broken, people responsible go to jail, that they get shut down, that doctors lose their license. This can't continue."
Said John Walker, another attorney for the families, "There doesn't need to be another name on that death lists. It needs to get stopped."
The Omidi brothers say there are greater risks with obese patients and that their clinics are professionally accredited and meet the highest standards. But they declined repeated requests from '20/20' for interviews.
And now even their own poster girl, Cassie Gibbons, has turned on them, saying she fears she may have been responsible for recruiting some of those patients who died.
"If any of those families lost someone because of me," she said, "my apologies are from the bottom of my heart, because I would never want anyone to lose anyone over this."