Dawud Abdulwali, 56, of Los Angeles, was arrested on an unrelated traffic charge on Tuesday, and was later booked on charges of aggravated arson and arson of a structure.
Electronic and physical evidence connected Abdulwali to the fire in the 900 block of West Temple Street, according to the L.A. Fire Department.
The blaze, which was deemed arson by a national response team with the Bureau of Alcohol, Tobacco, Firearms and Explosives, caused between $25 million to $30 million in damage to the Da Vinci Apartments and upwards of $50 million to $60 million in damage to an adjacent city building.
ATF officials said an accelerant was used, causing the flames to spread quickly across nearly an entire block. The intense flames shot up several hundred feet into the air and also caused extensive damage to the adjacent 110 Freeway.
"This was a historic fire in size and dollar loss, and required an equally significant joint effort by the LAFD, LAPD and ATF to solve. Our agencies spent thousands of hours processing the scene, running down leads, interviewing potential witnesses and performing numerous other investigative activities leading to Abdulwali's arrest," ATF Agent Carlos Canino said. "This investigation was a team effort from start to finish, which makes its resolution all the more gratifying."
Authorities spent 15,000 man hours investigating the fire, Canino said.
In December, two other men were considered persons of interest, but authorities have since ruled them out.
"Why do we think he (Abdulwali) did it? All the evidence that we have right now points to this person as a suspect," Canino said.
Details on an alleged motive were not immediately released. If convicted, Abdulwali faces a maximum sentence of life in prison. He is being held in lieu of $1 million bail.