JACKSON, Miss. â€"  Two shooting victims along Mississippi highways may have been killed by someone who posed as law enforcement and pulled them over late at night, authorities said Monday.

Lori Anne Carswell, 48, of Hernando, was found near her car on Mississippi Highway 713 in Tunica County on May 8 about 2:15 a.m. Three days later, Thomas Schlender, 74, of Raymond, Neb., was found in his car on Interstate 55 in nearby Panola County about 1:30 a.m.

Mississippi Bureau of Investigation Director Larry Waggoner said authorities were investigating whether the suspect was impersonating an officer and that is how the people ended up on the side of the road.

Both cars were found on remote stretches of highway and neither appeared to have had mechanical problems, said Mississippi Department of Public Safety spokesman Warren Strain.

If people have a suspicion that an imposter is trying to pull them over, they should call 911 or (asterisk)47, Strain said.

Shell casings were found at the scene of both shootings and were being analyzed and Strain said it would be premature to release other details about the type of weapon used.

The motive is still under investigation. Both cars were red, but Strain said that could be a coincidence.

Strain said Carswell's 1997 Pontiac Grand Am was found on the shoulder of the highway, but her body was found in the road near the intersection of Mississippi 713 and Interstate 69.

"We don't know how she wound up outside of the vehicle, but she was out of the car," Strain said.

Mississippi Highway Patrol spokesman Joey Miller said last week that Schlender's body was found in his car, which crashed into a divider in the median. He was alone in the 1999 Ford F-150 and no other motorists were hurt.

Miller has said five shell casings were found on the interstate after that shooting.

Tunica and Panola counties are near one another in the northern part of the state. Tunica County is most known for its casinos on the Mississippi River.