Casper police are investigating the death of a man who died at Wyoming Behavioral Institute three weeks ago.

Michael Schossow, 49, evidently stopped breathing as he slept during the early hours of March 31.

His roommates told a detective Schossow's breathing was abnormal the night before his death. He also advised nursing staff of an undisclosed medical condition and said he was not feeling well the day before.

Staff at WBI said shortly after 6 a.m., a mental health worker got on the radio and called for a nurse to respond to a patient room "right now."

When staff went into the room -- known as the "snoring room," where patients who snored slept -- they found Schossow laying on his back. He was reportedly pale, laying on his back in a bed.

Schossow's body was "cold to the touch" when staff found him. A nurse later said he had evidently been dead for some time.

A nurse found no pulse, but CPR was performed. Shortly thereafter, a nursing supervisor showed up with a medical kit and defibrillator.

Staff called 911 at 6:19 a.m. The Casper Fire Department had arrived and CPR was still underway when a police officer got to WBI. Schossow was pronounced dead at the scene.

A nursing supervisor later said Schossow had complained of a medical condition within the last day or two, according to the affidavit. Schossow was given an undisclosed medication to treat the condition, which has also not been disclosed. The nursing supervisor was not sure whether the medicine provided Schossow with relief, and said she'd have to check records to see whether he received more.

The supervisor said Schossow was supposed to be checked on every 15 minutes. Those checks were to be documented, noting whether Schossow was awake or sleeping and, if sleeping, what position he was sleeping in. The person checking needed to see at least three respirations.

Court documents make no note of WBI staff failing to check on Schossow.

Schossow's roommates said Schossow complained of not feeling well March 30. Schossow reportedly slept most of the day, didn't eat and complained of an undisclosed medical condition.

The roommates also said Schossow was typically a loud snorer, but the previous night had been worse than usual. They reported Schossow's breathing was heavier, then got quiet.

One of the roommates said he was awakened by Schossow's snoring several times that night and had to leave the room twice. At roughly 4-4:30 a.m., the roommate came out of the restroom and found Schossow's snoring had stopped. He went to bed and slept the rest of the night.

A nurse told the detective she checked on Schossow at 5:45 a.m. and noted Schossow's breathing was shallow. She began checking on him more frequently, and found his breathing was still shallow.

At 6:10 a.m. she went into the room, shook Schossow's left arm and found him unresponsive. That's when she got on the radio and called for another nurse.

In the affidavit, the CPD Detective requests a search warrant for the surveillance video at WBI and says she believes it will corroborate the patient checks.

K2 Radio News contacted WBI for a comment, and will update the story when they respond.

The Casper Police Department is waiting on autopsy and toxicology results before proceeding any further. The department declined to release further details, as it is an ongoing investigation.