Investigators have found no evidence that the Porsche carrying actor Paul Walker had mechanical problems before it crashed, killing the "Fast & Furious" star.
The investigation also ruled out debris or other roadway conditions as causing the car in which Walker was a passenger to careen into a light pole and tree.
"We're looking at speed and speed alone," a law enforcement official with knowledge of the investigation told The Associated Press. The official was not authorized to speak publicly about the investigation and spoke on condition of anonymity.
The Nov. 30 crash also killed the driver of the 2005 Porsche Carrera GT, Walker's friend and financial adviser Roger Rodas.
Investigators with the Los Angeles County Sheriff's Department have calculated a speed range at which they think the car was traveling but won't firm up that number until Porsche engineers come to California next month to extract information from onboard data collectors. The official would not disclose that range.
Though the car exploded in flames after the crash, the data recorders survived and may produce information to pinpoint the speed.
Rodas, 38, and Walker, 40, co-owned an auto racing team. Rodas also was a professional driver who competed in 10 Pirelli World Challenge GTS races this year.
The official told AP that the Porsche appeared to have negotiated a curve in the road just fine before crashing in an industrial park about 30 miles northwest of downtown Los Angeles.
"They were well out of the curve when they lost control," the official said.