Victor Marias was arrested Thursday and was being held without bail, according to jail records.
On July 19, firefighters responded to Kohler Street between Seventh and Eighth streets, where an outdoor fire extended to several commercial buildings, according to the Los Angeles Fire Department.
It took fire crews more than five hours to extinguish the flames, and one firefighter was injured.
LAFD arson investigators responded to the scene, and they obtained "security surveillance footage of the fire being set," fire officials said in a statement.
Investigators later linked three other fires to the same suspect, who was subsequently identified as Marias, who fire officials said was on active probation for a fire that damaged a building one block away from the Kohler Fire on Palmetto Street in August 2023.
The most recent fire Marias allegedly set occurred Thursday on Willow Street, where another fire had occurred on Sept. 22.
"In both cases, nearby residents provided surveillance footage showing the actions of collecting combustibles and setting them on fire," fire officials said.
Marias was arrested on suspicion of arson of a structure and arson of property, along with a probation violation.
"The assistance provided by witnesses within the community was critical in identifying and ultimately arresting the suspect. Their willingness to step forward and actively protect their neighborhood from harm is appreciated and commended," fire officials said in a statement.
Anyone with additional information was urged to contact the Los Angeles Fire Department at LAFDArson@lacity.org.