EAST PALO ALTO (CBS SF) — A $20,000 reward is being offered in a double murder case in East Palo Alto that resulted from a dispute at a Halloween party that ended in gunfire.

East Palo Alto police said Tuesday said the advocacy group Mothers Against Murder has offered the reward for information leading to the arrest and conviction of suspect Julian Rico Santana.

Julian Rico Santana (East Palo Alto Police Dept.)

According to police, officers responded on October 14 at about 2:44 a.m. to a shot-spotter activation on the 2500 block of Pulgas Ave., as well as a 911 call reporting a shooting at the location.

Two people were pronounced dead at the scene and two others were taken to the hospital with life-threatening injuries. The deceased victims were identified as Stockton resident Eduardo Alvarado Sandoval, 22, and East Palo Alto resident Mario Andres Vidalesmendez, 23.

Investigators determined that there was a private adult Halloween party at the business complex, and that a dispute occured which escalated into a fight and then gunfire.

The suspect, identified as Santana, fled the scene police said.

Anyone who sees the suspect was urged to call 911 and wait for police to arrive, and not attempt to apprehend the suspect.

Persons who may have witnessed the crime or have any information about the shooting were urged to contact the East Palo Alto Police Detective Aleyda Romero at 650-853-7249. Anonymous tipsters can send an anonymous email to epa@tipnow.org, text 650-409-6792, or leave an anonymous voice mail at 650-409-6792.