LITCHFIELD, Conn. | Before she was arrested on allegations of planning to shoot up two high schools, a Connecticut teenager was suspected of making threats against Columbine High School in Colorado.

Natalie Carpenter, 18, is accused of phoning in a threat to Columbine, The Register Citizen reported. She was arrested March 4 and pleaded not guilty to charges of conspiracy to commit assault, according to the newspaper.

Carpenter was arrested in Torrington for allegedly plotting with Peter Thulin, 19, to sneak into Danbury High School, hold students and staff hostage and shoot until “everyone was dead,” police said.

An attorney for Carpenter, John Cizik Jr., said Monday he had no comment. Her mother, Wendy, said Carpenter wouldn’t “hurt a fly” and was acting out while trying to cope with the loss of two close friends.

In her diary, Carpenter cited Columbine High School, where two teenage shooters killed 12 classmates and a teacher before killing themselves in 1999. She planned to shoot up Danbury and Stratford high schools to get back at students she believed bullied her, police said.

The threat to Columbine on Sept. 16 originated from a cellphone traced to Carpenter’s house in Stratford, police said.

Mark Techmeyer, spokesman for the Jefferson County Sheriff’s office in Colorado, said charges have not been filed. The alleged threat was one of nearly two dozen threats the department investigates every year at Columbine High School, he said.

“You look at the risk-value return,” Techmeyer said. “She’d have to (be) transported. It’s not a wise use of taxpayer dollars.”

The number of threats “would blow your mind,” Techmeyer said. “It’s nonstop. It’s not every day, but it’s a very regular occurrence. We investigate every single one of them, but 99.9 percent of the time, just about every time, they’re not credible threats.”