(CNN) For the second time in a week, a potential school shooting was thwarted by a tipster who gave authorities a heads up -- this time in the town of Middlebury, Vermont.

Authorities launched an investigation last week after a student told the principal at Middlebury Union Middle School that she or he overheard two teens planning to attack another student, police said.

Through interviews with multiple students, investigators learned that a 14-year-old planned to go to the school Tuesday at noon "and shoot a specific student, one in which he had problems with, and anyone else."

The second student involved allegedly said he could obtain a weapon from a relative.

"They provided us this information in pretty graphic detail," Middlebury police Chief Tom Hanley told CNN affiliate WPTZ . "As to what the plans were, very specific: date and time, target, where this was going to happen ... very specific. As opposed to the normal kind of idle chatter where there's nothing specific at all."

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