Investigators searching for remains of an 11-year-old boy who disappeared in 1999 will look again along the Whitewater River near Towanda, Butler County Sheriff Craig Murphy said Tuesday.

"We are going back to the river Saturday," searching for any evidence that could be connected to Adam Herrman's disappearance, Murphy said.

As with a search for Adam earlier this month, investigators on Saturday will be assisted by anthropology experts and search dogs, Murphy said.

Saturday's search, which will begin around 8 a.m., will go farther south along the Whitewater, for about 2 miles. The river runs along the west side of Towanda.

Valerie Herrman told The Eagle that Adam ran away the first week in May 1999 and never returned.

She said that Adam ran away after she spanked him with a belt. The Herrmans said they didn't report Adam missing because they feared the spanking would prompt authorities to take away Adam and his two younger siblings. For years, the Herrmans explained Adam's absence to relatives by saying he had been returned to the state's custody because he had behavior problems, the relatives said.

The relatives told The Eagle that Valerie Herrman had abused Adam for years -- an allegation she denies.

In an interview Friday, Butler County's chief prosecutor, County Attorney Jan Satterfield, said that the Herrmans are suspects in his disappearance and that the investigation could result in first-degree felony murder charges, with the underlying crime being child abuse.

The Herrmans have not been charged with any crime, and Valerie Herrman's attorney, Warner Eisenbise, has said that Valerie Herrman denies harming Adam.

Attorney Dan Monnat, whose firm is representing Doug Herrman, said, "Doug Hermann is innocent of any act resulting in the disappearance of Adam Herrman."

On Tuesday, Murphy said that his detectives are "still working through leads," including "a few leads that have sparked our interest." He wouldn't elaborate.

He asked that anyone with information about the case call investigators at 316-322-8817 or e-mail detectives at crimetips@bucoks.com.