Shooting in Birmingham, Ala.: Reward offered for information to catch attackers who left four dead and a dozen injured

Police continue to search for the perpetrators of an attack that left four people dead and a dozen wounded in Birmingham, Ala.

Two men and a woman were found dead by officers on the sidewalk of an entertainment complex while responding to an emergency call after 11 p.m. Saturday. A fourth person died at a nearby University of Alabama hospital.

Authorities identified the four fatalities as Anitra Holloman (21), Tahj Booker (27), Carlos McCain (27), and Roderick Lynn Patterson Jr (26).

Investigators believe that the shooting was a "hit" perpetrated by multiple attackers against a specific person or people, and that those who were around and struck by bullets were collateral damage. At the moment, the attackers and their target have not been identified.

They also detailed that they had collected more than 100 shell casings at the crime scene and that, according to some local media, at least one gun was equipped with a "Glock switch," which allows a pistol to fire automatically.

Mayor Randall Woodfin posted that information about the shooting could be rewarded with up to $100,000. "For every person touched by last night’s violence, know that your city weeps with you," he further wrote, and promised those affected, "You will receive justice for your loss."

The White House announced it was coordinating ongoing investigations with federal, state and local authorities.