Briana Soto, 17, was shot on March 26 outside her apartment near 11th Street and Lewis Avenue. She was apparently on her way home from work.
Soto ultimately passed away from her injuries.
During a news conference Tuesday, LBPD Chief Wally Hebeish released security images of a person seen walking in Soto's neighborhood about 10 minutes before the murder.
"The video we're releasing today, which was taken from security cameras, shows a suspect walking in the area just prior to the murder,'' Hebeish said.
"The suspect appears to be a male of unknown age dressed in dark clothing with a mask over his face,'' he continued. "We also have reason to believe the suspect ran southbound immediately following the murder and began removing garments.''
Hebeish says someone knows the person who killed Soto, and they will not stop working until they find him.
"I'm a father to a daughter, I'm a husband to a wife, I'm a public servant to a community," said Hebeish. "This is devastating for this family as it would be for any of us."
Last month, Soto's grandmother said the family was heartbroken. Maria Bravo told Eyewitness News in Spanish that her granddaughter was not a gang member and was a hard worker.
Anyone with information is urged to call Detectives Ethan Shear or Chasen Contreras at 562-570-7244. You can also call Crime Stoppers at 800-222-TIPS, or visit the Crime Stopper's website.