A Denver mother was allegedly shot to death by her husband Monday night while she was on the phone with a 911 police dispatcher.

The woman, who has been identified as Kristine Kirk, reportedly spent 12 minutes on the phone with 911 before she was killed, said a spokesperson for the Denver Police Department, reports CBS News' Crimesider.

Kirk, 44, called the police department at 9:31 p.m. to report that her husband, Richard Kirk, 47, was hallucinating and may have eaten a marijuana-infused edible. She told Denver public safety dispatchers that her husband was "talking about the end of the world and [saying] he wanted her to shoot him."

Initially, police say that Kirk's call was non-life threatening and that she requested medical help for her husband, whom she said was scaring the couple's three small children. However, the man then apparently got a gun out of their safe and shot her.

According to a police affidavit, 12 minutes into the call, the sound of "an apparent gunshot" was heard and "the victim was not heard on the call again."

Kristine Kirk was found dead with a gunshot wound to the head by officers.

The suspect is being held for investigation of first-degree murder and police have launched a homicide investigation in addition to an internal police investigation on how officers and dispatchers handled the call, reports USA Today.

Police did not release the 911 call or dispatch records due to the ongoing investigation. Richard Kirk reportedly confessed to the murder, telling a Denver police officer that he had killed his wife, according to the Denver Police Department's probable cause statement.