The FBI says DNA testing is inconclusive on soiled diapers thought to have been left by Pennsylvania police ambush suspect Eric Freen.

Edward Hanko, special agent in charge of Philadelphia's FBI office, says the diapers were exposed to the elements. He says "you can't say one way or the other" whether they were worn by Frein, the 31-year-old survivalist charged with killing a Pennsylvania State Police corporal and seriously wounding a trooper.

Police announced last week they had discovered diapers in the northeastern Pennsylvania woods where Frein is believed to be hiding, and that he might have worn them so he could remain stationary for long periods of time.

Hanko says the diapers might have belonged to Frein, but the testing can't confirm it.