Police Chief Greg Suhr on Wednesday said investigators are seeking more information on a man they believe may have abducted Kevin Collins from a bus stop in 1984.
The person, Dan Therrien, is described as a "person of interest" who died in 2008.
He was questioned in the days after Kevin was reported missing. Investigators only recently discovered Therrien's full criminal history because he had used several aliases.
Police last week dug up the backyard and garage of the home where Therrien used to live, which is blocks from the bus stop. Only dog bones were recovered.