Updated

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.

Investigators were not releasing many details, including whether they believe a single gunman is responsible or what type of weapon was used, said DeSoto County district attorney John Champion. Champion said the shootings are related, but there's no evidence to suggest that the victims knew each other.

"We do not have any witnesses at this point," Champion said. "We're asking the community for help."

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

Carswell just left work from Fitzgerald's Casino, also known as the Fitz Casino, in Tunica County, Champion said.

The interstate is more heavily traveled than the state highway where Carswell was found, but both areas are low-lying along the river with plenty of open fields in the northern part of the state. Authorities were investigating whether the suspect was impersonating an officer and that is how the people ended up on the side of the road, said Mississippi Bureau of Investigation director Larry Waggoner.

Champion acknowledged those rumors and did not rule out that theory. He advised motorists concerned about stopping for a law enforcement vehicle to call 911 to confirm that the traffic stop was legitimate. He said motorists also should put on their flashing hazard lights and drive to a safe, well-lit area until they receive notice that the stop was real.

Tunica County is most known for its casinos on the Mississippi River but law enforcement did not indicate any link to the businesses. Asked whether the situation could hurt the area's ability to lure tourists, Champion said, "I'm not concerned about the casino business."

Champion also said when asked that it wasn't obvious that any items were missing from the victims.

The sheriffs of DeSoto, Tunica and Coahoma counties are working together and law enforcement was saturating the area to find the suspect.

"The last thing that we want to do is to create a panic out there," Champion said.

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.

Shell casings were found at the scene of both shooting and were being analyzed.

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

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. She was returning home to nearby Hernando from work, police said.

"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. He was driving from Nebraska to Florida to pick up his grandson, authorities said.

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