Mexico's attorney general says authorities have yet to determine a motive in the alleged attack by federal police officers on a U.S. Embassy vehicle that wounded two CIA officers six months ago.

Attorney General Jesus Murillo Karam said Thursday that the still expects to get a strong sentence against the 14 officers charged with attempted murder.

The CIA officers were heading down a dirt road to a military installation south of Mexico City on Aug. 24 with a Mexican navy captain when a carload of gunmen opened fire on their SUV with diplomatic plates and gave chase. More vehicles joined in the pursuit, and the armored SUV was riddled with bullets.

The two CIA officers' injuries were not life-threatening. The captain was not injured.