MANSFIELD -- The investigation into the murders of three East Cleveland women led federal and local authoritiesto Poplar Street in Mansfield.

"What?! You're from Cleveland?" recalled neighbor Eva Carpenter, of her reaction when teams of investigators spread out on the street to interview neighbors.

"They were just coming out everywhere, these guys, and I'm like, 'What's going on?'" she said.

EXPANDED COVERAGE | East Cleveland murders

Law enforcement sources tell Channel 3 News, that new evidence suggests a possible link between accused serial killer, Michael Madison, and human trafficking.

Neighbors said investigators described vehicles, and a bi-racial couple, and asked them if they were seen in the neighborhood. None of the residents who spoke to Channel 3 News, said they saw the cars or the people whom authorities described.

Residents said investigators showed particular interest in a vacant lot where a dilapidated home once stood, before it was torn down a couple of years ago.

An FBI spokesperson confirmed that agents were canvassing the neighborhood on Tuesday, and said they are following up on all leads, but gave no other details.

Law enforcement sources tell Channel 3 News that investigators are not ruling out Madison's involvement in other crimes, or that he may not have acted alone in the murders.

Madison, 35, faces charges of kidnapping and aggravated murder in the slayings. He is a registered sex offender, who served four years in prison beginning in 2002.

East Cleveland Police responded to a call about a foul odor last Friday, anddiscovered a decomposed bodywrapped in plastic bags ina garage. Madison wasarrested after a short standoff with police.

Two more bodies were found Saturday, after police questioned Madison.

The first known victimwas identified as Angela Deskins, 38, of Cleveland. The last two victimshave been identified as Shirellda Terry, 18, of East Cleveland, and Shetisha Sheeley, 28, of Cleveland.

The possibility of a linkbetween the triple murders andthisMansfield neigbhorhood, some 85 miles away, has residents shocked andconcerned.

"It bothers me a lot because I have kids," said Korey Florence. "There are a lot of kidswho play out here."

"It's nerve-racking," said April Clinton. "Especially considering the history of the crimes [in East Cleveland], and that the women were all living close by."