AURORA, Colo. — A gunman barricaded inside his Colorado home fired shots at police from a second-story window before he was killed as SWAT officers stormed the home Saturday. Once inside, they found the bodies of three other adults, authorities said.

The suspect, whose name was withheld by police, held officers at bay for nearly six hours after neighbors reported gunfire at 3 a.m. inside the modest townhome in the Denver suburb of Aurora, said police Sgt. Cassidee Carlson. It wasn’t known if officers shot the suspect or if he shot himself.

Investigators said two men and a woman appeared to have been killed before officers arrived.

The suspect shot at police who approached the front of the home with an armored vehicle and who fired tear gas around 8:15 a.m. He was killed when he fired at officers from the second-story window about 45 minutes later, Carlson said.

“After we arrived on scene, there were no more shots fired up until he fired at us,” Carlson said. “During this time he was all over the house. He moved furniture. He was throwing things. He was agitated. He was irrational.”

A large front window was missing in the two-story townhome, the window’s mini-blinds in disarray. Bullet holes marked two upstairs windows, and neighbors milled about outside.

A fifth person escaped unharmed and called police to report that she saw three people inside the home who “appeared lifeless,” said Carlson.

A motive for the killings was unknown, and police had yet to say what weapon or weapons were used.

Police declined to release the victims’ names.

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