The shootings both took place last week, on two separate roadways some 55 miles apart, according to the report. Police say the victims were not acquainted.
Authorities in Mississippi are advising motorists to be cautious if they're pulled over, and to call 911 to verify that the police officer is legitimate. Pulling over into a well-lit, well-populated area is also advised. Scroll down to watch CNN's report on the Mississippi killings.