Wednesday"s mass shooting at a Southern California center for the developmentally disabled came on the heels of other U.S. massacres but differed from most in key ways, including the involvement of multiple people, including a woman, and an apparently well-planned escape route.
The attack in San Bernardino, a city of about 200,000 about 60 miles (100 km) east of Los Angeles, was perplexing, as police struggled to determine a motive and to find the shooters, who had fled in a black SUV.

 A man and a woman suspected of taking part in a shooting attack that killed 14 people and wounded 17 at a California social services agency on Wednesday died in a shootout with police hours later, authorities said.

One police officer was injured in the gunfight with the two suspects, who were confronted in their getaway vehicle after fleeing the scene of the shooting in San Bernardino, about 60 miles (100 km) east of Los Angeles.

Authorities also detained an individual seen running away from the vehicle, but investigators were not immediately sure that person was involved in the case, Police Chief Jarrod Burguan said at a news conference.

The chief added he knew of no possible motive for the shooting spree, which unfolded at 11 a.m. on the campus of the Inland Regional Center, an agency that serves the developmentally disabled.

The shooting rampage marked the deadliest U.S. gun violence since the massacre at Sandy Hook Elementary School in Newtown, Connecticut, in December 2012, in which 27 people, including the gunman, were killed.