Denver Police Department officers arrested a teenager Wednesday in connection with fatally shooting a girl in the head the day before.

Jasirr Simmons, 18, faces first-degree murder charges after he allegedly shot and killed a girl in a bedroom of a residence in the 5500 block of North Tucson Street, according to a news release and arrest documents provided by the DPD.

Officers first responded to reports of a self-inflicted gunshot wound just after 5:30 p.m. Tuesday, according to the documents. When they arrived, they found the girl lying on her back in a bed with what appeared to be a gunshot wound to the side of her head; paramedics pronounced her dead on the scene about 10 minutes later.

While examining the scene, investigators found two unfired cartridge casings on the carpet of the room, but could not locate the gun used in the shooting, according to the documents. Detectives later found it in a trash can on the property just before taking Simmons into custody.

Due to her status as a minor, the girl’s name was redacted from the arrest affidavit, though police did say she and Simmons lived with each other.

During follow-up interviews, one member of the household told police that Simmons had been out for a walk when he, the household member (who’s name was redacted), went to check on the victim. The man looked in Simmons’ room and saw her on the bed with blood around her and subsequently called 911. He did not remember telling dispatch the victim had shot herself.

Another person, whose name is also redacted, recounted to police that she had been on the walk with Simmons when, as they approached a trash can, he told her to keep walking, according to the documents. She did, and heard something getting dropped into the can.

Other members of the family and household said that they had been told the victim shot herself and Simmons had witnessed the incident, according to the documents.

Simmons was also interviewed by police at DPD headquarters before he was arrested, though the description of his statements to police are entirely redacted in the documents.

The final determination of Simmons’ charges will be made by the Denver District Attorney’s Office.