Philadelphia ? Dillon Cossey knew his online friend from Finland only as “sturmgeist89.” They met two or three months ago through the YouTube video-sharing site and found they shared common interests: the Columbine school massacre, violent videos and video games.

They traded e-mail, exchanged posts on a Web site dedicated to the Columbine killers and likely chatted online, said Cossey’s lawyer, J. David Farrell.

“They had discussed certain video games and shared videos with each other,” Farrell said. “Obviously, Columbine was a shared topic of interest.”

Cossey, who admitted plotting a school attack near Philadelphia, and Pekka-Eric Auvinen, who killed eight people and himself Wednesday in a high school in Finland, never talked about plans for any type of attacks, Farrell said.

Farrell said Cossey was “horrified” that Auvinen carried out the attacks. A rifle and other weapons were found in Cossey’s home, but his attorney said he was living in a morbid fantasy world.

“My client didn’t encourage him in any way,” Farrell said. “He had no indication that somebody he was communicating with actually was formulating an intent to commit a violent act.”

Farrell added that many nonviolent teens are drawn to the same things that brought Cossey and Auvinen together online.

“You can be sure that there are thousands and thousands and thousands of kids that are accessing these Web sites,” he said.

Finnish police said material seized from the computer of Auvinen suggests the 18-year-old had communicated online with Cossey, 14, who was arrested in October for allegedly preparing an attack at Plymouth Whitemarsh High School in suburban Philadelphia. The attack never took place.

Farrell said he showed Auvinen’s online screen name to his client Monday and he remembered communicating with him over the Internet, but didn’t know his real name.

Auvinen killed six students, a nurse and the principal Wednesday in Tuusula, about 30 miles north of the Finnish capital, Helsinki. He then shot himself in the head and died hours later at a hospital.