Lake Dallas, Texas ? Authorities on Thursday arrested a 26-year-old man in Kansas on a murder warrant in the death of his former girlfriend, who police suspect was placed in a concrete-filled barrel and dumped in the Red River.

Kansas Highway Patrol troopers, who had been on the lookout for the vehicle the man was driving, pulled over a car just after it passed through a toll booth Thursday near Wichita, Capt. John Walters said.

The car contained four adults and six children, including Steven Wiederhold, 26, who was arrested on a murder warrant. All four were in Sedgwick County Jail, and Texas authorities were on the way to Kansas, Walters said.

The Highway Patrol captain said he didn’t know if the other adults had any connection to the incident that prompted the arrest. All six children, including one thought to be the 3-year-old son of his alleged victim, were taken into protective custody.

Meanwhile, law enforcement officers have been searching along the Red River and in Oklahoma for a barrel and a body, fearing that 23-year-old Denise Ann Johnson was killed.

The Oklahoma State Bureau of Investigation, responding to a request from the Texas Rangers, checked out Lake Carl Blackwell near Stillwater and collected evidence from a U-Haul trailer turned in at Oklahoma City, said OSBI spokeswoman Jessica Brown. She said no body has been found and results of the search were pending.

Monday night, a Lake Dallas woman told police that a former boyfriend who had been living recently with Johnson came to her home on Sunday afternoon with another woman and with Johnson’s 3-year-old son, asking her to baby-sit the child while they “took care of some things.”

Police said he came back later and said he had killed her, put her body in a barrel and was going to wrap the barrel in cellophane and dump the body in the Red River.

Investigators said they found an indention similar to what a 55-gallon drum would make on the carpet of a closet in Johnson’s apartment. They also found several cans of empty air fresheners, sticks of burnt incense and baking soda scattered throughout the apartment in an apparent effort to conceal an odor.

Investigators also found empty containers of cellophane wrap and items used to mix concrete.

The Texas Department of Public Safety was asked to fly over the Red River, and authorities in counties along the river were asked to check bridges and roads dead-ending into the river for evidences that a barrel may have been thrown in.

On Tuesday, law enforcement officers learned that an Azle man had gone to authorities to report that the same man had asked him on June 1 to go with him to Denton County help dispose of a body in a barrel.