On Tuesday night, police arrested 41-year-old Mansfield woman Karen Read, whom multiple sources identified as his girlfriend.
She was charged with manslaughter, leaving the scene of a motor vehicle collision causing death and motor vehicle homicide.
Investigators say they have Ring Cam footage of the incident. According to prosecutors, O'Keefe knew the owners of the home where he was found, about two miles from where he lived; NBC10 Boston reported that property records show the homeowner has the exact same name and middle initial as a veteran police sergeant, though the Boston PD would not confirm it.
At Read's arraignment on Wednesday, prosecutors said the couple went to at least two bars together before driving to the home on Fairview Road around midnight; Read said she left O'Keefe there and went home because she was not feeling well. She said she made a three-point turn and left, but did not see O'Keefe enter the house.
She told investigators that she later tried to contact him, but couldn't get hold of him; the next morning, she said she noticed her tail light was broken.
She returned to the Fairview Road home hours later with a friend, and was heard saying "Could I have hit him? Did I hit him?" prosecutors said, per WCVB.
After finding him in the snow with severe cuts on his arm and head, eyes swollen shut and bleeding from the nose and mouth, they called 911, CBS Boston reported. The court heard that Read thought he might have been hit by a snow plow.