GREENBELT, Md. — Coast Guard Lt. Christopher Hasson was sentenced Friday to more than 13 years on weapons charges, in a case that prosecutors say thwarted a white supremacist’s terroristic plot to murder a long list of prominent Democrats and journalists.

Hasson, 50, of Maryland, pleaded guilty in October to four federal weapons charges. But federal prosecutors said the charged conduct only represented the “tip of the iceberg” of the evidence against him. They labeled Hasson a “domestic terrorist” shortly after his arrest and said he stockpiled weapons and was plotting to “murder innocent civilians on a scale rarely seen in this country.” They wanted a 25-year sentence.

Federal prosecutors laid out an extensive record of Hasson’s racists beliefs, a search history that included inquiries for the home addresses of Supreme Court justices, and an apparent hit list of media figures and Democratic politicians. Ahead of his sentencing, Hasson told U.S. District Court Judge George Hazel that he was “embarrassed” by his racist thoughts and web searches and sorry for the pain they’d caused.

“I have never hurt anyone in my life and I was not planning to in any way, shape or form,” Hasson claimed. He said he renounced his writings but was not claiming to be “magically cured of my biased thoughts.” But he said he’d work toward treating everyone equally, with the help of religious leaders.

The Hasson case has tested federal law enforcement’s ability to prevent domestic terrorist attacks and prosecute domestic terrorists. The United States doesn’t have a law that broadly makes acts of domestic terrorism illegal, and in general, federal prosecutors are hesitant to classify domestic terrorists as what they are.

While federal prosecutors did not charge Hasson with any terrorism-related offenses, they did ask for and were granted a terrorism sentencing enhancement that increased the range of the prison time Hasson faced under federal sentencing guidelines.

After the sentencing, U.S. Attorney Robert Hur of the District of Maryland told reporters that law enforcement would “look through the entire United States criminal code and use all of those tools in order to make sure that we can intervene and bring criminals to justice before harm falls our community.”

Liz Oyer, Hasson’s federal public defender, urged the court to consider Hasson’s long record of service to the country and his relationship with his family. She accused federal prosecutors of fearmongering by displaying Hasson’s cache of weapons in court, most of which he would be lawfully allowed to own were he not addicted to narcotics.

“We cannot incarcerate people for their private thoughts,” Oyer argued. She said that if white Americans had their private thoughts evaluated, we’d find a “terrifying number of closet racists,” but that the Constitution gives Americans the right to hold condemnable views.

She also said that Hasson didn’t treat anyone unfairly despite his views, and that she’d seen him “joking and laughing” with corrections officers ― “most of whom are Black” ― at the Maryland facility where he’s being held.

Dr. Stephen Hart, a defense witness, testified at length Friday about his violence risk assessment that declares Hasson a low risk. He said the government responded to the case “entirely appropriately,” but that Hasson didn’t need to be incarcerated based on being an ongoing threat to the public. He said Hasson was generally rational and clear-thinking, and called him a “civil and polite person.”