According to the Orange County Sheriff's Department, a man armed with a handgun walked into an AT&T store at 23842 El Toro Road in Lake Forest just after 9 a.m. He pointed the gun at several employees, ordered them to put their hands up and demanded cash.
The suspect then fled on foot with an unknown amount of cash.
A store security guard then asked to borrow a customer's vehicle and started chasing the suspect.
Meanwhile, a customer, who was sitting in his car outside the store, saw the masked gunman come out and gave chase.
"When he came out, I opened my door and yelled something at him. He kinda looked at me and then took off running around the corner. So I just jumped out and started running after him," said Scott Carr.
The chase continued for a few blocks, when another Good Samaritan stepped in to help. Scott Stoltz was driving to work when he saw a man wearing a ski mask run by and Carr right behind him.
"I saw people holding bank bags that he had dropped and things, and heard that he'd robbed somebody so I started to follow him," he said.
Stoltz then noticed the suspect was armed.
"I realized he had a gun. We've got an elementary school right around the corner, (and) he was headed in that direction. Things could go from bad to worse real quick so when he stepped into the street I decided I wanted to hit to him," said Stoltz.
The security guard appeared to have the same idea. They both hit the suspect, then collided with each other. The suspected robber fell to the ground.
Seconds later, an Orange County Sheriff's investigator answering the armed robbery call approached the suspect.
"I heard the fellow to my right identify himself as police and tell him to drop the weapon and get on the ground, and then there was a couple shots fired. And that was that," said Stoltz.
Authorities said the suspect was shot twice by the sheriff's investigator. He was transported to a local hospital with non-life threatening injuries.
Investigators allege he was trying to get to his car to get away when the Good Samaritans stepped in.
"Kind of surreal and I don't think it's sunk in fully yet... a little rattled," said Stoltz.
The AT&T store remained closed for the day.
Authorities were trying to determine if the suspect is the same man who robbed the store a few weeks ago.
The store was also robbed in 2009. In that case, different suspects stole dozens of iPhones and their getaway car was also located on the same street, three blocks from the store.