The fire caused different parts of the vehicles to melt, like the bumper, tires and fender.
The suspect was identified as 25-year-old Jonathan Arenas.
Friend said they were surprised, but said Arenas had the tools to cause this kind of damage.
"He would have equipment because he's an air conditioning guy," said the suspect's roommate Mark Halfon.
Halfon said his roommate had been acting odd lately and was out of work.
Police began getting calls about the fires at about 1 a.m. Some vehicle owners were shaken from their sleep from the flames, while others woke up to the damage.
Vandalism victim Mandy Meyers said a passing motorist stopped to tell her that her car was on fire.
"Some random kid just pulled over, banged on the door," she said. Meyers said after they got the fire out, they saw four other cars on fire.
"I thought, 'Oh no, this is a really sick, sick joke,'" she said.
It is unclear why the suspect blowtorched the vehicles. Police said the incidents appeared to be random crimes.
No one was injured.
At least one witness indicated there may be more than one suspect, so police may be making more arrests in this case. Anyone with information on these incidents is urged to call the LAPD Topanga station at (818) 756-4800.