Authorities say the 13-year-old male and female were stabbed on the third level of the mall in front of the AMC Theatres at 7:23 p.m. on Dec. 29. Both victims were rushed to a local hospital and underwent surgery.
Police were able to get surveillance footage from AMC Theatres that shows the suspect walking away from the scene.
Police say the male victim had six stab wounds: one to the chest, one to his left rib cage and four to his arms. The female victim had three stab wounds: one to the chest, one to her left rib cage and one to her upper left clavicle area.
They are in stable condition and are expected to make a fully recovery. Officials say they may be released from the hospital next week.
The suspect was described as a black man in his 40s, tall with medium build and possibly bald. He had a beard and mustache, and possibly wearing prescription glasses. At the time of the attack, the suspect was wearing a knit beanie cap, green/brown fatigue-type jacket, blue jeans and a black T-shirt.
Police say the suspect used a kitchen-type knife that had a black handle.
The motive for the stabbing remains unknown, but police say it appears to be a completely unprovoked attack. Anyone with information is urged to call the Redondo Beach Police Department tip line at (310) 937-6685.