Knox County Sheriff David Barber says investigators “have recovered significant evidence” in the search for clues in the disappearance of Tina Herrman, her friend Stephanie Sprang and Tina’s 11 year-old son.

That evidence apparently includes a tarp and trash bags found closed with duct tape in Foundation Park in Mount Vernon, Ohio, across the street from the home of prime suspect Matthew Hoffman who police say had Herrman’s 13 year-old daughter bound and gagged in his basement.  Police also revealed Hoffman had a receipt from the nearby Wal-Mart for a tarp and trash bags, along with a t-shirt and deli sandwich.

The Sheriff is encouraging anyone who sees anything unusual, including trash bags, to call authorities and not touch the possible evidence.  He’s also asking people to call who may have seen any of the three vehicles involved in the missing persons case: Herrman’s F-150 Ford Pickup, Sprang’s silver Jeep Cherokee or Hoffman’s Toyota Yaris compact.

Hoffman, being held in the Knox County Jail on $1 million dollars bond is also wearing a “suicide gown” to prevent him from harming himself.  The Sheriff said Hoffman hadn’t directly threatened suicide but gave indications to jail staff and investigators that led them to believe he might.

Hoffman now has a public defender, Attorney Bruce Malik, who declined an interview with Fox News Channel, telling this correspondent “I have nothing to say.”

The Sheriff says searches have been concentrated in Foundation Park as well as near Herrman’s home (which was found with significant blood spilled inside) and along a bike path near Kenyon College, where Herrman’s truck was found last Thursday and where a sheriff’s deputy also spotted Hoffman sitting in his car.  The deputy spoke to Hoffman but police didn’t enter his home until early Sunday when they found the girl.  The search for her mother, brother and family friend goes on.

Tomorrow afternoon authorities plan to release photos of clothing worn by the missing to try and job people’s memories and perhaps help speed their recovery.