A third teenager accused in what police call a Columbine-like plot to attack a high school helped make jelled gasoline and tested it last winter, a prosecutor said Monday.

Brown County District Attorney John Zakowski told Court Commissioner Larry Gazeley that the three friends started planning to assault the school with guns and explosives two to three years ago, based on the teens' statements.

Gazeley ordered Bradley Netwal, 18, jailed on $500,000 cash bail and set his initial court appearance for Friday. Netwal appeared by video conference from the Brown County jail. He kept quiet through the hearing, which was for the prosecutor to prove there was enough evidence to hold him.

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Police arrested William Cornell and Shawn Sturtz, both 17, on Thursday and Netwal, 18, on Friday on charges of conspiracy to commit first-degree homicide and arson. Another student alerted an associate principal to the suspected plot.

Formal charges are expected later in the week.

Netwal's attorney, Christopher Froelich, said the teenager was not involved in the plot.

Netwal has no prior criminal record, graduated from East High School last spring and plans to enroll in a technical school to become a game warden, Froelich said.

"He had a future, a very bright future," he said. "He didn't want to die at the hands of police."

But Zakowski said that like Cornell and Sturtz, Netwal wanted some revenge for problems he was having at the school. Netwal had known Cornell for three years, and they started talking about a Columbine-like plot in fall 2004, Zakowski said.

"He did admit that he and Bill made (jelled gasoline) and he knew Billy was purchasing weapons," the prosecutor said.

Cornell's lawyer, Shane Brabazon, could not be reached for comment Monday.

Police found nine rifles and shotguns, a handgun, about 20 "crudely made" explosive devices, camouflage clothing, gas masks, two-way radios and hundreds of rounds of ammunition at Cornell's house, authorities have said. At Sturtz's home, they found knives and ammunition, police said.

No guns or evidence of any plot was found in Netwal's home, Froelich said.

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