Police investigate motive in ambush of Houston area deputy

Shannon J. Miles, 30, is walked out of the Harris County Sheriff's Department in Houston on Saturday, Aug. 29, 2015. Prosecutors on Saturday charged Miles with capital murder in the killing of a uniformed sheriff's deputy who was gunned down from behind while filling his patrol car with gas. (Marie D. De Jesus/Houston Chronicle via AP)
Shannon J. Miles, 30, is walked out of the Harris County Sheriff’s Department in Houston on Saturday, Aug. 29, 2015. Prosecutors on Saturday charged Miles with capital murder in the killing of a uniformed sheriff’s deputy who was gunned down from behind while filling his patrol car with gas. (Marie D. De Jesus/Houston Chronicle via AP)

Investigators were trying to determine Sunday what may have motivated a 30-year-old man accused of ambushing a uniformed suburban Houston sheriff’s deputy filling his patrol car with gas in what authorities believe was a targeted killing. click here for complete story