Around 1:45 p.m. police found the suspect, 30-year-old Johnathon Inocencio, in the city of Elk Grove.
"Detectives issued a statewide BOLO for Johnathon and his vehicles. This BOLO was issued to all law enforcement agencies in California," police said.
Elk Grove PD made the arrest, and Livermore police are en route to take custody of him and his car.
"To our knowledge, the suspect resides here in Livermore," Both the suspect and the victim are transient and reside here in the creek. We believe the homicide is the result of an earlier feud that happened obviously prior to the homicide," said Officer Art Rosas with the Livermore Police Dept.
Officers responded at 4:06 a.m. to the shooting in the 2700 block of Las Positas Road, where a Walmart store is located, and found the victim with a gunshot wound to his upper torso, according to police.
They have not released information about the victim because they need to notify his relatives.
The Walmart on Las Positas Road is open and officers say this appears to be an isolated incident. They are aware of the homeless encampment here.
"As a police department we already have a homeless team that does outreach here on a regular basis and we obiviously when we have crime we are going to step up our enforcement efforts and of course our outreach team will continue their enforcement efforts and their outreach," Officer Rosas said.
Anyone with information is asked to call the Livermore police tip line at (925) 371-4790.
VIDEO: SKY7 flies over murder scene in Walmart parking lot in Livermore