Police arrested the teens on suspicion of murder, robbery and carjacking. Their names were not reported because of their ages.
The boys are accused of shooting Quinn Boyer, 34, of Dublin, in the head at point-blank range as he was stopped in his car at Keller Avenue and Hansom Drive at approximately noon April 2, the Oakland (Calif.) Tribune reported Tuesday.
Boyer never regained consciousness and was pronounced dead April 4. He was a paramedic with Rural/Metro Ambulance.
People in the neighborhood told police about a "suspicious vehicle" driving in the area on the day of the shooting, and investigators tracked down the abandoned vehicle at a nearby elementary school.
Oakland school district police officer Anthony Fergoso helped identify most of the teens through surveillance video taken near where the car was left, police said.
Police said the teens -- two are 14, two are 15 and one is 16 -- are all friends, but are not believed to be gang members. Their motive remains unclear.
"I'm deeply concerned about an unacceptable and disturbing trend where robberies and other crimes are being committed by young people 13 to 17," said police Chief Howard Jordan. "Young people are finding it very simple to point a gun and shoot someone."