Santa Ana police officers first responded to a call of a fight in the area of Cubbon and Baker streets and just minutes later, at about 10 p.m., they received another call of a person down in the 1100 block of W. Brook Street.
Officers and Orange County Fire Authority personnel discovered a 17-year-old boy on the sidewalk with stab wounds to his upper torso, police said. Paramedics pronounced him dead at the scene.
The victim's identity was not immediately released pending notification of family.
After a preliminary investigation, homicide detectives believe the stabbing may be gang-related.
Anyone with information is asked to call SAPD homicide detectives at (714) 245-8390 or Orange County Crime Stoppers at 1-855-TIP-OCCS.