Police in Alabama have identified three of four victims killed in a mass shooting over the weekend that also left 17 people injured.The incident happened Saturday when authorities said multiple suspects fired on a large group of people standing on a sidewalk in a popular nightlife district of Birmingham, Alabama.The Birmingham Police Department said three adult males and one female were killed in the incident. Police identified the deceased as 21-year-old Anitra Holloman, 27-year-old Tahj Booker, and 27-year-old Carlos McCain. The identification of the fourth adult male is pending.Birmingham Fire and Rescue, who responded to the scene, found Holloman, Booker and McCain lying unresponsive with multiple gunshot wounds upon arrival. They were pronounced dead at the scene.UAB Hospital staff pronounced the additional male gunshot victim dead at the hospital.RELATED STORY | 4 killed, at least 17 wounded in shooting at Birmingham, Alabama nightlife districtAuthorities believe the shooters used machine gun conversion devices in the incident. Over 100 shell casings were collected at the scene, police said.Detectives believe the shooting was not random and stemmed from an isolated incident where multiple victims were caught in the crossfire, said Birmingham Police.No suspects have been taken into custody as of the police departments latest update.Anyone with information is urged to contact BPDs homicide unit at (205) 254-1764 or Crime Stoppers at (205) 254-7777.An investigation remains ongoing.