Just weeks before being sentenced for killing three people in Alexandria, Charles Severance took out a pen to write a long letter to two Washington Post reporters.

The serial killer’s eight-page screed, printed on lined notebook paper, takes aim at The Post, D.C. Police Chief Cathy L. Lanier, and the parents and boyfriend of Alison Parker, the Roanoke reporter shot to death on live television in August.

“I am an internationally recognized expert witness on Mental Disorder,” Severance wrote from Alexandria’s detention center, where he is being held.

“My highly esteemed credentials are prominently posted at mental­disorder.com so I’m not kidding.”

The handwritten missive is addressed to me as “Ian Shapira Man of Letters,” and my colleague as “Dana Priest Lady Scholar of the Explaining Class.” It is rambling and vulgar and filled with slurs against Jews, gays and women, along with random references to sadism, the Taiping Rebellion in 19th-century China and Edmund Burke.

A jury in Fairfax, Va., found Charles Severance guilty of all 10 criminal counts against him in the murder of three Alexandria residents over the course of a decade. (Ashleigh Joplin/The Washington Post)

The white-bearded Severance does not address his murder trial in Fairfax County, where in November he was convicted of the 2014 slaying of music teacher Ruthanne Lodato, the 2013 shooting of regional transportation planner Ronald Kirby and the 2003 killing of real estate agent Nancy Dunning.

All of the victims were shot at their homes during the day, terrifying the city. Jurors recommended that Severance, who did not testify, be sentenced to life in prison without parole in each case. A judge is expected to impose that penalty at his sentencing Jan. 22.

In his letter, Severance denounces the Alexandria sheriff, without using a name, as “mentally ill.” But he devotes much of his ink to commentary about a recent Post profile that I wrote about Chris Hurst, the boyfriend of Parker, who was a reporter at WDBJ.

[They knew they’d marry one day, then a gunman stole their future on live TV.]

“I figure the Misery Index for the Explaining Class was permanently elevated one degree of dangerousness since the hideous August 2015 Captain John Smith Mountain Lake Murder. It’s the kind of story that will never go away despite the long Goodbye,” Severance writes, referring to the title of a series on hospice care that the Roanoke station did partly in Parker’s honor. “ ‘Terror is passion,’ observed the great 18th century social thinker Sir Edmund Burke ‘that always produces delight when it does not press too close.’ ”

His letter was postmarked Dec. 26, and its envelope bears a stamp from his current residence: the William G. Truesdale Adult Detention Center at 2001 Mill Rd. in Alexandria. It was not discovered in The Post’s mailroom until Jan. 11.

An attorney for Severance, Christopher Leibig, declined to comment.

In a handwritten letter to The Washington Post, Charles Severance criticizes the newspaper, the District’s police chief and the relatives of a slain Roanoke, Va., television journalist, among others. (Matt McClain/The Washington Post)

Severance’s bizarre writings were a critical piece of evidence during his trial last year. The missives — some handwritten and seized from his car, others gathered by various electronic means — were often hateful, violent and incoherent, although his attorneys pointed out that they also encompassed more innocuous themes, such as history and board-game development.

[The evidence against Charles Severance]

Prosecutors contended that Severance’s writings, at times, seemed to describe his crimes. In one document, for example, he wrote, “Knock. Talk. Enter. Kill. Exit. Murder” — an apparently perverted version of a biblical parable. He also wrote of violence toward those in law enforcement. Defense attorneys, though, contended that the documents were little more than the random musings of a man who battled mental illness later in his life.

In court, Severance was known to act strangely, sometimes interrupting the judge and sparring over his constitutional rights. He was declared competent to stand trial and generally bristled at his characterization as someone in need of mental health treatment.

Some pages of his letter to The Post are decorated with desultory arrangements of words and phrases signaling that Severance is following the news. “Paris, San Bernadino, and Beirut,” he writes on one line. “ISIS ISIS ISIS,” he scribbles elsewhere.

Severance directs much of his anger at The Post.

“You guys are lackeys and toadys and word-whoring propaganda sychophants for the legitimate institution of pharmaceutical toxic psychiatric policing north of the Rio Grande. It’s disgusting.”

Matt Zapotosky contributed to this report.