A witness driving near Mill Swamp Road in Smithfield on March 13 reported that she saw an individual appear to run over a bald eagle with a red ATV, according to the statement of facts filed in the Eastern District of Virginia. The witness said she saw the individual drive in a circle and run over the eagle at least three to four times before he dragged it into the woods.
During an investigation, police officers from the Virginia Department of Game and Inland Fisheries learned that Thacker owned and was driving a red ATV that day, according to court documents. Thacker admitted to shooting and killing the bald eagle and led the officers to the location where he dragged the eagle.
Thacker told police that he felt the need to protect his property from the eagle since it had been killing small game and taking fish from the pond, the court documents state.
He also told police that he tried to scare the eagle off with warning shot, but it did not leave. He admitted to investigators to first using a .22 caliber rifle to shoot the eagle and then using a pistol to "finish the eagle off," but denied running it over with the ATV, according to the statement of facts.
In an interview with agents from the United States Fish and Wildlife Service several days after the eagle was killed, Thacker expressed that "too much emphasis is placed on bald eagle protection because the birds are a menace," court documents state. The USFWS seized the firearms used to kill the eagle.
After a necropsy was performed on the eagle, officers determined that the adult male eagle was in good nutritional condition and found remnants from a .22 caliber projectile inside of it, according to the statement of facts. The medical examiner speculated that the gunshot wounds would not have been immediately fatal to the eagle and determined that the immediate cause of death was blunt force trauma to the head resulting in a fractured skull and associated hemorrhage.
"The medical examiner found no evidence that Thacker used a pistol to kill the bird as he had claimed," the court document states.
Although Thacker "intially was not truthful in regards to how he killed the eagle," he fully admitted to shooting the bird and running it over with his ATV in the court documents filed today, Joshua Stueve, director of communications for the Easter District of Virginia, told ABC News via email.
According to the plea agreement, Thacker must forfeit all assets involved in the offense, including the .22 caliber rifle. Since Thacker jointly owns the Yamaha Big Bear all-terrain with his sister, he has agreed to forfeit a sum of $960.
The pistol seized from Thacker was determined to not be "part of the criminal conduct in this case" and will be returned to Thacker, the plea agreement states.
Thacker's defense attorney, Robert Rigney, did not immediately respond to ABC News' request for comment. Thacker will be sentenced on Oct. 23.
ABC News' Jack Date contributed to this report.