A 17-year-old had recently broken up with his girlfriend when he tracked her down in a car chase, fatally shot one of her companions and then took his own life in front of horrified onlookers, police and witnesses say.

The gunman, identified by police as Andrew Brown, also critically wounded another teen with a shotgun blast and beat the girl with the butt of a shotgun, Lt. Skip Arms said Tuesday.

The girl's injuries were not considered life-threatening.

Police said Michael Fisher, 18, was killed. He was driving a Ford Explorer where Tiffany Howard, 16, had sought refuge Monday afternoon because she had "some concerns" about Brown and breaking up with him, Arms said.

Fisher, Howard and Howard's friend Jeremy Vasquez were riding in Fisher's Explorer along with two other teens when they spotted Brown following them and showing a shotgun, Arms said.

They had called 911 and were trying to reach the safety of a police station when Brown attacked them in what witnesses described as a residential area, Arms said.

Arms said the teens reported that Brown rammed their Ford Explorer from behind with his Chevy Suburban before he pulled up beside them and fired a shotgun blast, wounding Vasquez.

When the teens stopped to help Vasquez, Brown turned around, got out of his vehicle and fired several blasts that killed Fisher, Arms said.

Brown began beating Howard with the shotgun but then dropped it and return to his Suburban, Arms said. When the first police officer arrived, Brown pulled a second shotgun from the vehicle and fatally shot himself, Arms said.

Arms said Brown got the shotguns from his home, but it was not immediately clear who owned them. The first shotgun was empty when police recovered it, Arms said.

The two other teens riding with Fisher, Howard and Vasquez were not injured.

All the teens attended Colorado Springs high schools except for one of the uninjured teens, who was home-schooled, Arms said.

The coroner said Fisher died of multiple gunshot wounds. Brown's death was a suicide, the coroner said.

"I feel helpless. I just saw two lives taken," said Stephanie Edwards, who lives in the area and had been walking to a supermarket when she saw the shootings.

Felina Swaba said she was driving by with her brother when she saw the girl being beaten.

"I thought he was going to shoot her," Swaba said. She said she got out of her car and screamed at the assailant to stop when her brother, Phillip, told her to back off.

"I told her, 'Stop, he's got a shotgun,"' Phillip Swaba said.

Felina Swaba said the gunman shot himself when he saw a crowd gathering and a police officer arrived.