A former Marine Corps Reservist from Virginia has agreed to serve 25 years in prison Thursday as part of a plea deal for firing shots at the Pentagon and other military building in 2010. No one was injured during the incident.

Yonathan Melaku, a 23-year-old naturalized citizen from Ethiopia, was arrested in June when he was spotted in Arlington National Cemetery.

He was carrying a backpack containing potential explosive material and notations referring to jihad and al Qaeda chief Osama bin Laden.

Authorities say Melaku had been planning to desecrate the graves of several military veterans who lost their lives in Iraq and Afghanistan.

Formal sentencing for the ex-Marine has been delayed until April so a pre-sentence report can be prepared and to allow Melaku's lawyer to request a mental-health evaluation.

But Dana Boente, the top assistant U.S. attorney for the Eastern District of Virginia who prosecuted the case, said there was no evidence that Melaku was unstable.

Boente called the crimes "a campaign of calculated and sustained attacks against military installations and memorials in northern Virginia."