MARSHFIELD, Mass. -- The trial started Monday in the case of a former Marshfield High student who was accused of plotting an attack on his school.

NewsCenter 5's Amalia Barreda reported that Joseph Nee, 21, faces charges of conspiracy to commit murder, promotion of anarchy and threatening to use deadly weapons at school.

Witness for the prosecution, Dan Farley, 20, and Nee went to police in September 2004 to tell them that a third teen was plotting to blow up the school.

"He said, 'They are all sitting ducks,'" Farley said.

Farley testified that Nee first talked about attacking the school in December 2003.

"He asked me what I would do if he said he was going to shoot up the school," Farley said.

Farley said that Nee and Tobin Kern, now serving a 10-month sentence following his conviction for conspiracy to commit murder, hatched the plot.

Farley said that they called themselves Natural Born Killers and worshiped the students behind the Columbine school massacre.

"We did it because we were bored and drunk," Farley said.

He testified about Nee's threat if anyone told officials.

"The defendant said that if anyone is to talk to the cops about that your tongue would be cut straight out of your head,"

Defense attorney Tom Dreschler questioned Farley about the immunity deal he cut with a prosecution and his work as a police informant. Dreschler also questioned Farley's claims that he never did any drugs beyond marijuana and alcohol -- testimony that contradicted Farley's previous sworn statements.

"We you lying when you said you did drugs?" Dreschler asked.

"Fine. I did cocaine. I've never dome acid. I've never done mushrooms," Farley said. "I can't remember. I can't remember."