A Butler County man who was arrested on terrorism charges has pleaded guilty to planning the kidnapping and execution of a U.S. military employee and an attack on a police station.

Prosecutors released previously sealed documents, including a plea agreement, on Thursday that detail the national-security case against Munir Abdulkader, 21, of West Chester.

The FBI Joint Terrorism Task Force arrested Abdulkader on May 21, 2015 after he purchased an AK-47, ending the task force’s two-year surveillance of him.

Unsealed court documents and the FBI gave this detailed account of Abdulkader’s case: