COLUMBUS, Ohio (AP) -- A former Ohio doctor accused of killing a pregnant woman last year by injecting her with heroin after she answered a Craigslist ad pleaded guilty Thursday in her death and that of her nearly full-term unborn child. Ali Salim entered the pleas in Delaware County Court north of Columbus ahead of his trial scheduled for next week. He faces 37 years in prison at a December sentencing. Salim, 44, pleaded guilty to two counts of involuntary manslaughter in the deaths of Deanna Ballman and her unborn daughter, who was to be named Mabel Lilly. Ballman, 23, was nine months pregnant when she died. Salim also pleaded guilty to tampering with evidence and abuse of a corpse. He also entered a type of guilty plea to a charge of rape under which he maintains his innocence but acknowledges prosecutors had enough evidence to convict him. The tampering with evidence charge alleges Salim erased photos and video of Ballman from his phone, though the images were later recovered by investigators, said Kyle Rohrer, assistant Delaware County Prosecutor. The guilty pleas avoid any uncertainties from a trial and gave Salim the chance to take responsibility in court, Rohrer said. Ballman's mother and sister attended the hearing but declined to comment. The family appreciates the work of investigators and will speak at sentencing, their lawyer Greg Helser said Thursday. Salim remains free on house arrest on $1 million bond. Ballman was last seen alive on July 31, 2012, when she left her home in suburban Columbus, telling her family she was answering a Craigslist ad for a housecleaner. She called her mother a few hours later saying she was feeling dizzy. The call was then lost and her family couldn't reach her again. Ballman's body was found in the back of her car the next day on a rural road a few miles from Salim's house in an upscale neighborhood. Salim's attorney, Sam Shamansky, has said Ballman was prostituting herself to feed a drug habit. He said Thursday the guilty plea avoided the possibility of consecutive life sentences for Salim, who was originally charged with two counts of murder. Shamansky said he'll present evidence favorable to Salim at sentencing, but in a dignified manner given the Ballmans' loss. Salim "is extremely remorseful and has obviously accepted complete responsibility" for the death of Deanna Ballman and her unborn child, Shamansky said. Authorities say there's no evidence that Ballman was a drug user, but they have said she was responding to a personal ad, not a job ad. Rohrer declined to discuss the allegations Thursday. He said a full presentation of the state's case would be made at sentencing. Women who previously answered ads placed by Salim reported being accosted, sexually assaulted or asked to be alone in the house while he painted the human digestive system on their abdomens, according to police records. Salim is also the target of a $40 million lawsuit filed by Ballman's family earlier this year blaming him for her death. That lawsuit, which also named Salim's employer and Craigslist, has been on hold during the criminal case.