ASHLAND, Ohio -

Authorities are looking for a 33-year-old Ohio woman who went on vacation in North Carolina with her two children and her boyfriend but didn't return with them.

Ashland County sheriff's Capt. Carl Richert said his office was working with North Carolina investigators on the disappearance of Lynn Jackenheimer of Ashland, who traveled 500 miles to Nags Head, N.C.-area, and has been missing since July 4.

"I don't believe she is in Ashland County. I don't believe she ever came back from Nags Head," Richert said.

Dare County Sheriff's Chief Deputy Steve Hoggard said they searched sunday from 5 p.m. until dusk for Jackenheimer.

Dogs, deputies and helicopters aided in the effort.  Deputies said they also walked Hatteras Island but found no sign of the 33-year-old mother.

Richert said that investigators want to find Jackenheimer's boyfriend, described as a "person of interest" in the case.

Police said the man returned the children to the Ashland area and left them with his family. Richert said a relative reported the boyfriend made comments indicating he may have harmed Jackenheimer.

"I want to report a possible murder," Jake Summerfield told Ashland County dispatchers. "My brother was in North Carolina with his ex-girlfriend.  He came back and said he strangled her and dropped his kid off and left."

Police asked for any tips about Jackenheimer, who is about 5-foot-8 with brown hair and blue eyes.

Richert said deputies have the man's cellphone and surveillance video showing him driving a 2009 dark metallic gray four-door Honda Civic at an Ashland Bank around 10 a.m. Sunday. The license plate is FMX-7540.

The cellphone was obtained in Ashland, but Richert declined to specify the details.

More than 150 friends, relatives and supporters gathered for a candle-lit prayer vigil Monday night. The vigil was led by Rev. Sanford Mitchell of Trinity Lutheran Church, where Jackenheimer attended youth group activities.