Tustin police Sgt. Ryan Newton said the three suspects intentionally drove into Orange County to commit crime.
"All of these individuals do have several felony arrests and convictions all out of the Los Angeles area," Newton said.
On June 15, the Secret Service agent had finished working a detail in Los Angeles -- on the same night President Biden was in town for a re-election fundraiser -- and was arriving home near Edinger Avenue and Jamboree Road.
"The Secret Service agent was not on duty," Newton said. "He was off duty and he is the victim of this violent crime and he defended himself with his weapon. We do believe it was just a crime of opportunity and that he wasn't targeted."
The victim had just parked his car and was walking home when the incident happened.
"He was approached by a van and a suspect got out of the van, approached him with a firearm, put it into his face and asked for his bag," Newton said.
According to police, after a brief scuffle the suspect, Jamonte Fitzgerald Johnson, stole the victim's bag and got into the van.
"At that point another one of the suspects attempted to exit the van, exhibited some threatening manners and that's when the shooting occurred," Newton said. "The victim in this case defended himself with his firearm and he fired into that van."
During their investigation authorities discovered that the second suspect, Bertran Claude Bell, had been shot.
Bell, Johnson and the third suspect, E'Shon Dwayne Dodson, were all arrested this month.
"Items of evidence were collected and sent to the crime lab. We ultimately got a DNA hit on some of these evidence which started this investigation and led us to our primary suspect," Newton said.
The off-duty Secret Service agent was not hurt during the robbery.
The suspects now face charges including robbery and assault with a deadly weapon.