A 21-year-old man in Arizona shot and killed his roommate after an apparent altercation, police say. Zachary Penton reportedly admitted to responding officers at a home near Chandler Heights Sunday that he shot 41-year-old Daniel Garofalo, FOX 10 Phoenix reports.

Garofalo was reportedly pronounced dead at the scene, where authorities discovered a handgun they "believe was used" in the fatal shooting. Penton has since been booked into Maricopa County jail on murder charges. A separate report from ABC 15 adds that "a fight" led to the shooting and that Penton reportedly called the police to the scene himself. He was taken into custody without incident. A Twitter account that ABC 15 says belongs to Penton appeared to make a vague threat regarding his roommates on Friday:

Police are still actively investigating the shooting, as the events leading up to the altercation remain unclear. Speaking with ABC 15 Monday, police said they haven't officially confirmed the Twitter account in question belongs to Penton, though they are currently "looking into the possibility."

The Maricopa County Sheriff's Office and the Chandler Police Department did not immediately respond to Complex's request for comment.