Towanda ? Investigators used search dogs Saturday to scour a wooded area along the banks of the Whitewater River as they continued looking for a Kansas boy whose disappearance went unreported for a decade.

Adam Herrman was 11 years old when he went missing in 1999 from his adoptive parents’ mobile home in Towanda. If still alive, he would be 21 years old now.

His disappearance finally came to light last week when authorities — acting on a tip to the Sedgwick County Exploited and Missing Children’s Unit — searched the empty lot in Towanda where the family’s mobile home once stood.

Butler County Sheriff Craig Murphy said no specific tips led investigators to the wooded area just west of Towanda on Saturday, but the area is a popular hangout for local youths.

Murphy expressed doubts before Saturday’s search because so much time had passed since the boy disappeared. Saturday night, Murphy said the effort failed to turn up anything of interest regarding Adam’s whereabouts.

No charges have been filed against Adam’s adoptive parents, Doug and Valerie Herrman. Authorities have said consideration of charges of any kind would wait so investigators can concentrate on the search.

The family’s attorney, Warner Eisenbise, has said Adam had a history of running away. Eisenbise said his clients thought the boy had done so again when he disappeared in 1999 and felt “very guilty” not reporting it at the time.

Eisenbise has said the family had nothing to do with the boy’s disappearance, but acknowledged that other charges may be coming in connection with the case.

The Department of Social and Rehabilitation Services confirmed Thursday that the Herrmans continued to receive adoption subsidy payments for Adam after he was missing, but the agency could not immediately determine how much. The department said it was researching the case.

The Herrmans adopted Adam and two of his younger siblings, family members have said.

Adam was placed in protective custody for two days in 1996 after a report of physical abuse, Social and Rehabilitation Services officials have said. The boy was returned to the Herrmans after authorities reviewed the evidence and found the report unsubstantiated.