Andre de Andrade, who worked with Guerra at AKM Images/GSI Media, said his friend "always played by the rules," KNBC-TV in Los Angeles reported.
"I'm not aware of him doing anything illegal," Andrade said. "Some people will say he's just another crazy paparazzo trying to make the money. Actually, he was not a paparazzo. He was just another kid from New Mexico."
Pop star Bieber was not in his Ferrari when a photographer who stopped to take pictures of it was fatally struck by another car in Los Angeles, TMZ says.
One of the Canadian teen singer's friends was driving the luxury sports car and another was in the passenger seat at the time of the Tuesday night incident, the entertainment industry news website reported.
Police had pulled the Ferrari over because of the driver's alleged speeding and the paparazzo got out of his vehicle to take photos, while the sports car was on the side of Sepulveda Boulevard.
The photographer was instructed by police to return to his car, but was hit by another vehicle and killed as he crossed the highway on his way back, TMZ said.
The names and ages of those involved in the incident were not immediately available.
"While I was not present nor directly involved with this tragic accident, my thoughts and prayers are with the family of the victim," Bieber said in a statement released by his publicist to the Los Angeles Times. "Hopefully this tragedy will finally inspire meaningful legislation and whatever other necessary steps to protect the lives and safety of celebrities, police officers, innocent public bystanders and the photographers themselves."
Thibault Mauvilain went to the crash site to pay his respects to his fellow photographer, a man he identified only as Chris.
"I know a lot of people say, 'Oh, just another crazy paparazzo trying to make the money.' Actually, he was not a paparazzo, he was just another kid from New Mexico," Mauvilain told KNX-AM, Los Angeles.