Police have not confirmed the victim's identity, but ABC7 News has learned that the victim was a well-known community leader in East Palo Alto. He co-founded an outreach group, helping others recover from substance abuse and incarceration.
Police said that there are so many surveillance cameras inside and outside the mall, that they should have no problem finding the gunman.
Late into the night, police searched the west side parking lot of the Hillside mall for clues, anything that might tell them who shot the man. It happened at 5:40 p.m. after witnesses heard the single gunshot.
"Officers responded quickly, actually we arrived on scene within two minutes and discovered a victim, a 54-year-old male who sustained a single gunshot wound," said San Mateo Police Lt. Mike Bruncardi.
The man was transported to a local hospital but died. No one else was injured.
Police believe the gunman escaped in a car. Several witnesses saw the vehicle and may be able to identify it.
The incident happened outside the mall and San Mateo Police Chief Susan Manheimer says the public was never in any danger. In fact, the mall was never closed.
"A targeted incident, that it was an incident that at this point, we don't believe is related to Hillsdale mall, but more likely between two individuals," said Manheimer.
This is the first homicide in San Mateo this year. The murder motive out is still unclear.
While several witnesses were interviewed, police are still asking the public for help.
"This is odd for here, pretty good area, not too many problems," said shopper Jeff Bowyer.
"I was just kind of shocked to see all the security people and the roped off area and didn't know exactly what had happened, but I asked a women next to me and I'm a little bit surprised because you usually don't hear about that type of thing," said shopper Debbie Yandell.
As soon as police have a description of the suspect's vehicle, they will begin putting that information out to the public.