The King County Prosecutor has charged a Tacoma woman with first-degree manslaughter for allegedly shooting and killing her aunt’s boyfriend with a single shot to the back of his head on Dec. 30 in Auburn.

Deanna Kahealani Fale, 21, claims she did not intend to shoot 46-year-old Mark Dearden, that his death was the unintended, tragic outcome of a bit of ordinary family horseplay, and that she did not know the pistol with which she shot him, a Smith and Wesson M&P 9 mm, was loaded.

Fale is in King County jail on $250,000 bail. Her arraignment is at 9 a.m., Jan. 18 in Courtroom GA in Kent.

Here is what happened, according to the certification for determination of probable cause, written by Auburn Police Detective Francesca Nix and forwarded to the prosecutor’s office:

Fale notified police dispatch at 4:35 p.m. that she had just accidentally shot someone at an apartment on F Street Northwest. Responding officers found medics trying to save Dearden’s life, but they pronounced him dead in the apartment at 4:57 p.m., the victim of a single shot just behind his left ear.

According to the report, a crying Fale told an Auburn Patrol officer at the scene, “I didn’t mean to do it.”

Fale told police that Dearden was walking into the bathroom when he told her to stop messing with the gun, which she just had taken from her boyfriend. She said she did not believe that the gun was loaded when she pointed it at Dearden, jokingly told him to shut up, and pulled the trigger, mortally wounding him.

Fale said she then dropped the gun near a couch and immediately called 911. She told police she had not been arguing with Dearden, and she had no issues with him.

One of the occupants of the apartment at the time of the shooting, Mataio Fale, a relative of Fale’s, told police he and a friend had found the gun in a ravine in Federal Way sometime prior to the shooting, and that no one knew to whom it belonged.

Fale’s boyfriend told police that at the time of the shooting, he knew there was a magazine in the gun but thought that the gun was not loaded with bullets. He told police that Deanna Fale and Dearden were playing around, and Fale was manipulating the gun in her hand when it went off.

According to the report: “When Deanna was asked if she believed her actions were reckless, Deanna stated, ‘yes.’ ”

Here is what Senior Deputy Prosecuting Attorney Adrienne T. McCoy told the court in her request for bail:

“The defendant has admitted, and her own family corroborates, that she grabbed a firearm from her boyfriend, racked the slide, pointed it at the back of (Dearden’s) head, pulled the trigger and shot him to death.

“While she said she did not ‘think’ the firearm was loaded, she told police that what she did was reckless. She also told police that she and her family often play with firearms in the same manner. Her terrible judgment resulted in the death of an innocent man. Her lack of care and poor judgment makes her a danger to the community,” McCoy said.