Phoenix Police arrested the man for DUI back in December, but sometime between his arrest and the two mile drive to the police substation, he stopped breathing.
The man's family said the officers left the man on the floor of a patrol car, and that action resulted in his death.
Conflicting autopsy reports are the crux of the case. The question remains whether Edgardo Figueroa died because of alcohol poisoning, or police negligence.
A lawyer for the family filed a notice of claim with the city this week, saying police officers are to blame.
26-year-old Figueroa died while in Phoenix Police custody after being placed in the back of a patrol car. He was arrested for DUI on Christmas Day.
None of that is in dispute, but what is --the cause of death.
The Maricopa County Medical Examiner report says he died of acute alcohol intoxication.
An independent medical examiner says that is wrong.
"It's not a death that is attributed directly to alcohol," said Dr. Philip Keen.
Figueroa's family hired Dr. Keen, the former Maricopa County Chief Medical Examiner, to take a second look at his body. He says alcohol may have been a factor in the death, but not the reason.
"That level of 0.29 for an adult, ought to be more like a 0.5," he said.
Keen says Figueroa died because his breathing was obstructed.
"I attributed the death to probably asphyxia, positional asphyxia," said Keen.
It's a finding which Figueroa Family's lawyer says is the direct result of the police officers negligence.
According to the notice of claim, Figueroa's wife "saw him lying face down" on the floor in the back of a patrol car with his hands cuffed behind his back.
When the officer arrived at the substation two miles away, Figueroa was "unresponsive with no pulse."
"He slumped against the seat and he didn't breathe well," he said.
The family is asking for $7 million for wrongful death.
"His chances for survival would have been maximized if someone watched him, and made sure that his airway was open, and that he was breathing," said Keen.
Phoenix Police declined to speak about the notice. The city has two months to respond to the notice of claim.
If the city does not, the family's lawyer plans to file a lawsuit.