Shooting near Harvard University leaves 2 with life-threatening injuries, suspect ID'd

Two people were shot and left with life-threatening injuries after a gunman began shooting into traffic in Cambridge on Monday afternoon near Harvard University, according to officials.

Middlesex County District Attorney Marian Ryan said during a press briefing after the incident that a gunman with an assault-style rifle was "actively firing in an erratic fashion at various vehicles."

The shooting occurred in the vicinity of Memorial Drive and River Street before 1:30 p.m.

A trooper and a civilian, a former Marine, fired their weapons and struck the gunman, who was later identified as Tyler Brown, multiple times, according to the DA. Brown is under arrest and is hospitalized, Ryan said.

Brown will be charged with two counts of armed assault with intent to murder, possession charges with respect to the weapon, as well as a variety of other charges, Ryan said. He was under the supervision of probation for a previous crime, according to the DA.

The two people who were struck by gunfire were in their vehicles at the time.

Aerial footage from ABC News' Boston affiliate WCVB showed the gunman being apprehended by police at the scene.

WCVB footage also showed a black Dodge sedan off the side of the road after an apparent crash.

A rifle was seen on the grass in the area, according to WCVB.

Massachusetts Governor Maura Healey said in a statement that there is no ongoing threat to the public, but asked that residents "avoid the area to allow public safety personnel to do their work."

Lisa Schill, a witness to the shooting, told WCVB she was in a school van on the way to pick up kids at school. She said she left the van and began running from the incident on foot.

"I was running for my life," Schill told the publication.

ABC News' Chris Barry contributed to this report.