The man awoke to find his girlfriend with a plastic bag over her head, his attorney says.
A man was charged with manslaughter in the death of his girlfriend, who passed out with a plastic bag over her head while sniffing laughing gas.
Michael Lemay sold laughing gas as a recreational drug and provided the gas at home to 24-year-old Sara Knollinger, investigators said after filing criminal charges Friday.
Lemay, 23, and three friends took Knollinger to the fire station in the community of Port St. John on April 23, saying she needed help. But she had been dead for so long that rigor mortis had set in.
Investigators say Lemay obtained nitrous oxide under a false name, filled balloons with the gas, used some at home and sold others at rave clubs.
Prosecutors and investigators believe this is the first time that delivery of nitrous oxide has led to a manslaughter charge in Florida.
"This is not necessarily an innovative use of the law," said Assistant State Attorney Mike Doyle. "It is just rare that a set of facts present themselves in a manner appropriate to its application."
An autopsy concluded Knollinger suffocated under the plastic bag while inhaling nitrous oxide, which is sometimes used as a dental anesthetic.
Knollinger's father Tom appeared with Sheriff Phil Williams when the charges were announced to plead with parents and young people to be aware of the danger of inhaling the gas.
"I'd like to prevent other parents from having to sit where I am now," he said.
Lemay's attorney, Tom Yardley, said the sheriff and prosecutors were grandstanding.
"This whole thing was a tragedy, but it was an accidental death. She killed herself huffing," Yardley said.
He said Lemay had urged Knollinger to come to bed after a party, but she stayed up and continued to inhale the gas.
"He awoke to find her on the couch with a plastic bag over her head and a tube to the empty canister," Yardley said.
Lemay, who is free on bond, moved to Maine to live with his parents and underwent drug rehabilitation after Knollinger's death.