From [HERE] Detroit police still don't know how an off-duty officer's holstered gun discharged and killed a woman who reportedly embraced him from behind during a backyard party, according to news reports.

Adaisha Miller -- who would have turned 25 today -- died of a single gunshot wound that passed through a lung and struck her heart early Sunday. Although the medical examiner ruled her death a homicide, Police Chief Ralph Godbee Jr. said a preliminary investigation indicates it was an accident, the Detroit Free Press says.

The shooting happened about 12:30 a.m. Sunday at the home of Officer Issac Parrish. Godbee said at a news conference that Miller was dancing behind Parrish and touching his waist when his department-issued Smith & Wesson M&P 40-caliber semi-automatic somehow fired.

Godbee said the Neoprene holster, being worn on the officer's right, was soft enough for the trigger to have been pulled with the gun stowed. The gun has an external safety but not an internal trigger safety, police said. For the gun to fire, the trigger, which requires 6.5 pounds of pull to discharge, must be pulled completely, Smith & Wesson says.

"Somehow, in the course of dancing with the individual to his rear and touching his waist, his Detroit Police Department-issued weapon discharged, striking Ms. Miller," Godbee said. "There is absolutely no indication that the officer placed his hand on his weapon at all."

His version differs slightly from an account given by John Goldpaugh, a lawyer for the Detroit Police Officers Association, who told a Free Press reporter he spent several hours with Parrish after the shooting.

According to Goldpaugh, the 38-year-old Parrish was dancing with his wife when Miller came up behind him and tugged at his waist. "And the gun went off," he said. "It's a fluke accidental shooting."

He said the officer is "devastated by what happened."

A former Michigan State Police firearms examiner told the Associated Press that key aspects of the investigation will be the angle of the entry wound and gunpowder residue.

"I'm having a great deal of difficulty understanding how a weapon that's pointed at the ground can be turned literally 110 degrees minimum to be in an upward position to strike someone," said David Balash.

The Wayne County Prosecutor's Office will conduct a separate, independent review, which is standard in police shootings.

Miller's mother, Yolanda McNair, is wondering why an off-duty would carry a loaded gun at a party in his own backyard.

"The story keeps changing," she told the Free Press. "There's no logical reason."

She said her daughter was invited to the Saturday night fish fry at Parrish's home by friends who knew him. She apparently did not know Parrish.

McNair said she waved good-bye to her daughter, a massage therapist, as she left for the party.

"Then I saw her at the morgue," she said.