Wednesday night, two people were fatally shot in the Antelope Valley city just before 6 p.m. in the 800 block of E Avenue J-12, according to the Los Angeles County Sheriff's Department.
The two were brought to a local hospital and pronounced dead there. Several other people were also injured.
Further details weren't immediately available.
The night before, three separate shootings left two people dead and at least one injured.
Lancaster shootings: 2 dead after 3 separate incidents within a few hours
Investigators are looking into whether any of the four separate shootings, less than 24 hours apart, are related.
Lancaster Mayor R. Rex Parris says his city feels overwhelmed and under-resourced.
He's asking the Los Angeles County Board of Supervisors to provide more law enforcement resources from the sheriff's department.
"We're running at 50% of the number of deputies that we need," Parris told Eyewitness News. "They knew this was going to happen. They knew it was building. For whatever reason the county will not give us enough officers to protect this community, even though we pay for it."