Alexandria, Virginia (CNN) -- A former Marine Corps reservist pleaded guilty Thursday to shooting at the Pentagon and other military-related buildings and to trying to desecrate graves at Arlington National Cemetery containing the remains of veterans who fought in Iraq and Afghanistan. 

Yonathan Melaku entered a guilty plea to three counts: damaging U.S. property with a firearm, using a firearm in a crime of violence and attempting injury to veterans' memorials on U.S. property. 

Melaku, a 23-year-old naturalized U.S. citizen who was born in Ethiopia, was arrested June 17 at the cemetery. He had a backpack with four plastic bags each containing 5 pounds of ammonium nitrate, material commonly used in homemade explosives. He also had numerous 9 mm spent shell casings; black paint and a notebook with Arabic statements mentioning al Qaeda, Osama bin Laden, the Taliban and the "Path to Jihad." 

In the statement of facts document signed by Melaku, he admitted he "intended to desecrate and injure grave markers by spray-painting the markers with Arabic statements and by leaving the ammonium nitrate he was carrying at the sites of these grave markers." 

Melaku did not have all the components needed to make a bomb. In a search of his home, investigators found a typed list that included various components including batteries, wire and a "digital kitchen countdown timer." But he had not obtained all of those items. 

Melaku admitted to five shootings with a legally owned handgun at military buildings in Northern Virginia between October 17 and November 2 of 2010. He said he attacked the Pentagon, Marine and Coast Guard recruiting offices and he twice fired at the National Museum of the Marine Corps. 
Did Melaku have all the things he needed to make an explosive device?
Melaku did not have all the components needed to make a bomb