(Reuters) – A U.S. Coast Guard lieutenant who was arrested in February after prosecutors said he was plotting to attack Democratic politicians and TV personalities pleaded guilty on Thursday to weapons and drug charges, changing his earlier not-guilty plea.

Lt. Christopher Paul Hasson, 50, who has been in federal custody since his arrest, previously denied the four charges contained in an indictment handed up shortly after his arrest.

In U.S. District Court in Greenbelt, Maryland, Hasson pleaded guilty to unlawfully possessing firearm silencers and the painkiller Tramadol, as well as possession of firearms by an addict of a controlled substance.

Hasson was scheduled to be sentenced on Jan. 31, when he will face a maximum combined 31 years in prison, Maryland U.S. Attorney Robert Hur said.

“I look forward to the opportunity for the government to present additional evidence to the court at sentencing,” Hur said in a statement.

After Hasson's arrest, authorities said they seized a cache of 15 firearms and more than 1,000 rounds of ammunition from his Silver Spring, Maryland, home.

Prosecutors had said Hasson was a “domestic terrorist” and a self-described white supremacist with a list of potential shooting targets, including House of Representatives Speaker Nancy Pelosi and MSNBC television host Joe Scarborough.

“There is an intent to murder innocent civilians,” Assistant U.S. Attorney Jennifer Sykes said at a Feb. 21 court hearing, citing a draft email Hasson allegedly wrote but did not send.

Coast Guard photo

Authorities found 15 guns and more than 1,000 rounds of ammunition when they searched the apartment of Coast Guard Lt. Christopher Paul Hasson
(U.S. Attorney's Office in Maryland)

Hasson's attorneys said prosecutors had “mischaracterized and sensationalized” a case that was actually about a husband and father of two with a prescription opioid addition whose only crime was unlawfully possessing drugs and firearms.

“Mr. Hasson was not plotting a terrorist attack or any of the abhorrent acts that the prosecution has repeatedly speculated about but never actually charged,” public defenders Liz Oyer and Cullen Macbeth said in a statement after the plea change.

“Mr. Hasson accepts that he will be fairly punished for the crimes he did commit,” the attorneys said, adding that their client regrets the “pain and embarrassment” he caused his family and the Coast Guard.

Hasson, a former U.S. Marine, had been assigned to Coast Guard Headquarters in Washington.

The Coast Guard said Thursday that Hasson was still on active duty pending its own administrative investigation, which will start after the conclusion of the criminal case, The Washington Post reported.