Authorities are questioning a man over suspicious highway stops in central Mississippi after two fatal shootings last week that apparently occurred during phony police stops in the northern part of the state.
As of late today, the man being held in Humphreys County, Miss., James Lucas, was merely "under investigation," being questioned on the Wednesday night incident and not charged with a crime, a Humphreys County sheriff's official said.
Police could not say whether the two recent incidents were related to the earlier fatal shootings.
"We're just going to say these are isolated incidents in our county and we're going to deal with that first," Sam Dobbins, an investigator with the Humphreys County Sheriff's Office, told ABCNews.com.
However, Dobbins added, other police agencies in the state, including the Mississippi Department of Investigation, also were investigating, apparently giving the case a broader scope.
At least one detail may not match up to those reported in the fatal shootings: Wednesday's incidents involved a blue Mercury Grand Marquis, possibly the one Lucas was driving when he was pulled over around noon today in Yazoo City, Miss., according to ABC News affiliate WAPT in Jackson, Miss.
The fatal incidents, however, were believed to involve a gold Ford Crown Victoria.
'DON'T PULL OVER'
The Humphreys County incidents occurred after Mississippi authorities urged drivers to question whether anyone pulling them over really was a police officer.
"We urge everyone to be cautious while driving, especially at night," the Tate County Sheriff's Office posted on its Facebook page. "If someone attempts to pull you over with flashing lights and you feel unsure of stopping, DON'T PULL OVER. Use your cell phone and dial 911 and if it's a real officer then the dispatcher will confirm it for you and if it's not a real officer they will send help to you."
"Our deputies have been told not to overreact if someone does not immediately pull over," the sheriff's office wrote. "Your safety is our primary concern."
Two drivers were killed on northern Mississippi highways within days of each other and investigators in multiple counties and federal officials were working to find out who may be behind the killings.
One driver, Tom Schlender, 74, from Nebraska, was found in his car on Interstate 55 in Panola County on May 8 about 1:30 a.m. Three days later, Lori Carswell, 48, from Mississippi, was found near her car on Mississippi Highway 713 in nearby Tunica County about 2:15 a.m.
A Police-Type Car and Flashing Blue Lights
The recent cases occurred along U.S. 49 in Humphreys County, which is in central Mississippi, between 9 p.m. and midnight Wednesday night.
"We received some calls last night for a blue car similar to a police car, a Mercury Grand Marquis, that attempted to stop two vehicles," Dobbins said.
Although Dobbins believed the person in the Grand Marquis approached the victims' cars in plain clothes, the suspicious car's occupant evidently made indications his was an official vehicle.
"He displayed flashing blue lights, yes he did," Dobbins said. "That's what we call impersonating a police officer."
Both pulled-over drivers grew suspicious and sped off toward Yazoo City in neighboring Yazoo County, where Lucas and the car later were found being brought back to Humphreys County.
One of the two victims grew frightened and fired a gun when he saw the Grand Marquis following him, Dobbins said.
Later, one of the victims identified the seized car as the one involved in the highway stop, Dobbins added.
Dobbins would not comment on whether or not Lucas or the occupant of the Grand Marquis displayed a weapon.