The 38-year-old drifter was also charged with 16 counts of assault with a deadly weapon and 17 counts of hit-and-run in the weekend incident that left an Italian newlywed dead and 11 other pedestrians injured.
The murder charge carries an added special circumstance of using a vehicle as a deadly weapon and Campbell could face life in prison if convicted, CNN said. Campbell remained jailed on $1 million bail.
The motive for Campbell's alleged rampage remained unknown; however, Los Angeles police have been piecing together an outline of his peripatetic adult life, the Los Angeles Times said.
Campbell had apparently worked at treatment facilities for people with substance abuse problems in Colorado and Phoenix over the years. Campbell quit his job in Phoenix in June, but the manager of the facility said he had not experienced any problems with him.