One of the four suspects in the robbery at the Gold N Treasures store at 2550 San Ramon Valley Blvd. was killed during the robbery when one of the victims shot him and another suspect was arrested June 1.
On Wednesday, San Ramon police arrested Gregory Jamal Louis, 22, in the 200 block of B Street on suspicion of murder and robbery.
Louis was booked into the Martinez Detention Facility and was scheduled to appear in court for an initial arraignment.
A week ago, police arrested Krishneel Prasad, 19, on Stewart Drive near his Hayward home at 1:15 p.m. on suspicion of robbery, conspiracy and false imprisonment.
Prasad was booked into the Martinez Detention Facility and his bail was set at $300,000.
Police are continuing to search for the fourth suspect, who fled the robbery.
The four men, one of them armed, attempted to rob the store at around 4:35 p.m. on May 30 while it was occupied by employees and one customer. One of the victims pulled out a gun and shot the armed man.
The injured suspect, later identified as Kibrom Bairu, 18, of Hayward, staggered out of the store while the other three suspects fled.
Bairu was taken to San Ramon Valley Regional Medical Center, where he was pronounced dead.
Anyone with further information about the incident or the remaining suspect's whereabouts is asked to call San Ramon police at (925) 973-2700.