AURORA, Colo. (AP) — Four people, including an armed suspect, died after an hours-long police standoff Saturday at a Colorado townhome, authorities said.

Police Sgt. Cassidee Carlson said a SWAT team was called after gunshots were heard at the Aurora, Colo., home at about 3 a.m. Investigators said three victims, all of them adults, appeared to have been killed before officers arrived.

Carlson said the suspect shot at officers at about 8:15 a.m. and was killed during a gunfight about 45 minutes later when police entered the home. It remained unclear if officers shot the suspect or if he shot himself.