A spokeswoman for the Wayne County, Mich., Health and Human Services Department also said there was a "strong possibility" Renisha McBride had marijuana in her system, but a followup test was recommended to confirm, WWJ-TV, Detroit reported Thursday.
Meanwhile, prosecutors were expected to announce Friday whether they would file charges against the white homeowner who fatally shot McBride, who is black, in the face with a shotgun as she was standing on his porch in Dearborn Heights Nov. 2 after she was apparently in a car accident.
The death was ruled a homicide.
Wayne County Prosecutor Kym Worthy said she was considering all the evidence before deciding whether to charge the unidentified 54-year-old male.
Attorney Gerald Thurswell, who represents McBride's family, told WWJ, Detroit, the fact McBride was intoxicated when she was shot "probably makes her less of a physical threat to anybody."
"The bottom line in this whole case is that he was in his house, the door is locked, he has a phone," Thurswell said of the homeowner. "All he had to do was call 911. Maybe she would have been arrested because she was drunk -- but she'd be alive."
The Detroit Free Press said police received a 911 call about a car accident involving a woman speeding down the street, hitting a vehicle and then leaving the scene. Police spokesman Sgt. Michael Woody said no officers were dispatched immediately because the accident was deemed low priority. Emergency services received a second call that the woman who hit the vehicle had returned, but when officers arrived, she was gone again.
The homeowner who allegedly shot McBride has not been identified. The Detroit Free Press said the man told police he thought McBride was trying to break into his home and his shotgun fired accidentally.
Michigan's "self-defense" law states a person may use deadly force if "the individual honestly and reasonably believes that the use of deadly force is necessary to prevent the imminent death of or imminent great bodily harm to himself of herself or to another individual," The New York Times said.
Family members and friends said they think McBride was looking for help after the accident and expressed concern the man who shot her had not been arrested, the Times said.
Civil rights activists in Detroit also recalled the cases of Trayvon Martin, the unarmed black teenager who was fatally shot in Florida, and Jonathan Ferrell, a black man shot to death by a police officer in Charlotte, N.C., when he sought help after a car accident, the Times said.
Legal experts told the Times said a criminal case would probably be complicated, in part because there were few witnesses.
"There's likely only one eyewitness to this because the woman can't tell her story," said Peter Henning, a professor at Wayne State University Law School. "There are things we're just never going to know."