Word of the potential connection came Friday as the first funerals were held for members of the five-man U.S. Forest Service crew that was overtaken Oct. 26 as the blaze roared through the San Jacinto Mountains, 90 miles east of Los Angeles.
Cameras secretly placed atop utility poles in remote areas captured details of a car registered to a man who said he had sold it to Raymond Lee Oyler months ago, said the official, who requested anonymity because the case was continuing.
The official said detectives then began investigating Oyler for a string of arsons and found evidence linking him to last week's deadly fire. The cameras did not catch Oyler setting that fire, the official said.
Oyler has been charged with murder and arson. Although prosecutors described the evidence against him as overwhelming, they have not provided many details of the case.
Oyler has denied setting the deadly Esperanza fire, one of an unusually high number of arson blazes in the region this year. It destroyed 34 homes and charred more than 60 square miles before being contained Monday.
At the first funeral Friday, assistant engine operator Jason McKay was remembered for his strength, his sense of duty and for helping deliver a baby several months ago.
"Jason McKay gave his life while protecting someone else's life and property, and even though we honor his noble service today, at the same time we mourn his passing," said Jeff Barbour, a pastor at High Desert Church in Victorville.
Funerals for the other firefighters were scheduled into next week. A public memorial service for all five was planned for Sunday.
Oyler has pleaded not guilty to five counts of murder, 11 counts of arson and 10 counts of use of an incendiary device. The charges include seven fires in June, one in July, one in September and two in October.
The charges are punishable by life in prison without parole or the death penalty. Prosecutors said they will decide in the next 60 days which sentence to seek.