NORRISTOWN — Investigators searching the hard drive of a boy who plotted to attack a Pennsylvania high school found no evidence he tried to encourage others, including a teen who went on a killing spree at a high school in Finland.

Authorities still believe Dillon Cossey, 14, communicated online with Pekka-Eric Auvinen, a teenage outcast who killed eight people and himself at a school near Helsinki. But prosecutors said the search turned up no evidence of e-mails, instant messages or other communication between the two.

"I personally don't think we're going to find evidence that Dillon was soliciting other people to go commit other school shootings," Montgomery County District Attorney Bruce Castor said. "He's too cooperative and anxious to help."

Finnish police said Monday that material seized from Auvinen's computer suggested the 18-year-old had communicated online with Cossey, who was arrested in October for allegedly preparing an attack at Plymouth Whitemarsh High School.

Cossey knew Auvinen only by his screen name, according to his attorney, and was "horrified" when he found out about last week's attack.

Auvinen killed six students, a nurse and the principal Nov. 7. He then fatally shot himself in the head.