Diego Dominguez, 36, of Rancho Cucamonga, was arrested Sunday. He is suspected of shooting and killing 45-year-old Dean Sena as he worked at a strip mall on Arrow Route and Hermosa Avenue around 11:20 p.m. Saturday.
According to San Bernardino County sheriff's homicide detectives, the suspect entered the mini-mart wearing a hooded sweatshirt and a bandana covering his face. He was wielding a handgun and had glasses on.
That's when one of two clerks inside the mini-mart ran outside the store and flagged down Sena, deputies said. The second clerk remained behind the counter, opened the cash register, and gave the suspect an undisclosed amount of money.
When the suspect exited the store, he ran into Sena. Deputies say there was some sort of altercation and several shots were fired.
San Bernardino County Sheriff's Department Cpl. Randy Naquin says Sena was armed, but was not able to fire his weapon.
"The victim was not inside his vehicle, but it appears that he didn't even know that the suspect had a weapon, so the victim did have a weapon and wasn't able to actually take it out of his holster and fire off any shots," said Naquin.
Sena was pronounced dead at the scene.
Dominguez was stopped and detained around 8:30 a.m. Sunday after leaving his residence in a vehicle, authorities said. Detectives served a search warrant on Dominguez's vehicles and his home, located in the 9900 block of Placer Street, a block away from the crime scene.
Dominguez was eventually arrested for the murder and the robbery. He was booked at the West Valley Detention Center. Dominguez is being held without bail.
Sena was a married father of two. Customers and residents said Sena always had a smile and a kind word, and they can't believe he was gunned down in cold blood. Sena's friends said they know his first concern was for those in harm's way.
"I don't think he would have changed anything, because that was Dean. He was trying to protect the lives of others and he wound up losing his own," said one friend.
Friends said that Sena was planning on retiring from security work May 1.
Kurt Riggens of Rancho Cucamonga was stunned to learn of the murder that took place so close to his home.
"You never expect this stuff to happen in your neighborhood, and especially right across the street, you know, and to have someone lose their life over a few dollars, if that's what they took, it's crazy," said Riggens.
The investgation is ongoing. Anyone with any information is urged to contact the San Bernardino County Sheriff's Department at (909) 387-3589.