The incident happened shortly before 11 p.m. Saturday at 10th Street West and West Avenue J-4.
Investigators said deputies from the Los Angeles Sheriff's Department's Lancaster station attempted to stop a man for a bicycle traffic violation. Deputies said he was riding his bike without a headlight in a dimly lit area.
The suspect, identified by family members as 26-year-old Christian Cobian, allegedly ignored deputies' commands to stop and a chase on foot ensued. Deputies have yet to confirm the identity of the suspect.
Authorities said the suspect reached for his waistband. Sheriff's officials said the deputies feared for their safety and shot the man.
No deputies were injured.
The man was shot and pronounced dead at the scene. Neighbors said they heard several shots fired.
A second person at the scene was taken into custody, but was later released because he had nothing to do with the incident.
Cobian's mother, Carmen Cobian told Eyewitness News that she loved her son very much and does not understand why deputies shot and killed him. She said her son would never carry a gun or hurt anyone.
Sheriff's officials confirmed that no weapons were recovered from the scene.
Other family members, including Christian Cobian's younger sister and cousin, gathered at the scene of the shooting Sunday morning, some sobbing uncontrollably.
In a press release sent Sunday afternoon, sheriff's officials said their suspect was wanted for an Inglewood felony narcotics warrant. He was on probation for the felony crime of receiving stolen property and also had three felony convictions on his record. Deputies said he was an Inglewood gang member who had recently moved to Lancaster.
Deputies said if the suspect was caught, no bail amount would have been permitted for his release.
The deputies' use of deadly force was under investigation by the Los Angeles Sheriff's Department, the Los Angeles District Attorney's Office and the Office of Independent Review.
City News Service contributed to this report.