PHILADELPHIA (AP) &#8212 A teenager who admitted plotting a school attack near Philadelphia had chatted online about the Columbine massacre with a teenage outcast who killed eight people and himself in a high school shooting in Finland, the Pennsylvania boy’s attorney said Monday.

But the teen was “horrified” when he found out about the Finnish attack and said he never would have suspected him of following through on a violent act, the attorney said.

Finnish police said material seized from the computer of Pekka-Eric Auvinen suggests the 18-year-old had communicated online with Dillon Cossey, 14, who was arrested in October for allegedly preparing a attack at Plymouth Whitemarsh High School in suburban Philadelphia.

Cossey’s attorney, J. David Farrell, said he showed Auvinen’s online screen name to his client Monday and he remembered communicating with him about video games and the 1999 Columbine massacre in Colorado and exchanging videos they found on the Internet.

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

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 later at a hospital.

Police in Finland said they had not yet been in contact with their U.S. colleagues about a possible link between the two teens.

In Pennsylvania, detectives were running the name of the Finnish shooter through the computer seized from Cossey, who admitted in juvenile court to planning an attack.

“We had heard when we first got this guy that he had contacted other people through Web sites,” Plymouth Township Deputy Chief Joe Lawrence said. “We wouldn’t be shocked by it.”

Tipped off by a boy Cossey tried to recruit, Pennsylvania authorities searched his home last month. They found a rifle, about 30 air-powered guns made to look like higher-powered weapons, swords, knives, a bomb-making book, video of the Columbine attack and violent notebooks.

Finnish investigators have said Auvinen left a suicide note for his family and foreshadowed the attack in YouTube postings. On Monday, Rabbe von Hertzen, a detective in the case, said Auvinen is believed to have written the suicide note on Nov. 5, suggesting he had planned the attacks for at least two days.

Police have described Auvinen as a bullied teenage outcast consumed with anger against society.

Cossey told a friend he wanted to pull off an attack similar to Columbine. Prosecutors and Farrell have said he felt bullied.

Two weeks after arrest, Cossey admitted to three felonies – criminal solicitation, risking a catastrophe and possession of an instrument of crime – in Montgomery County juvenile court. He is in juvenile custody, where he could remain for six-and-a-half years.

The attack on the Pennsylvania school never took place.

Authorities have accused Cossey’s mother, Michele, of helping him build his weapons stash. She is charged with illegally buying her son a .22-caliber handgun, a .22-caliber rifle and the 9 mm semiautomatic rifle, which had a laser scope. Her preliminary hearing is scheduled for Dec. 13.

Farrell said he doesn’t know whether Dillon Cossey had contact with other people who could pose similar threats, but planned to explore that possibility with investigators and his client.