A former Capital Gazette columnist received a letter Thursday that police suspect came from the man accused in a shooting at the paper’s Annapolis newsroom last week that left five people dead.

It would be the fourth such letter reported in less than a week.

While working for the Capital Gazette, Eric Hartley, now an editor at the Virginian-Pilot in Norfolk, wrote a 2011 column about Jarrod Ramos, now charged with murder in the five deaths. The column became the focal point for Ramos’s years-long animus toward the newspaper — in the court system through lawsuits and appeals and on social media.

In an email to The Washington Post, Hartley said he found a “pink greeting-card-style envelope” in his office mailbox Thursday morning. It was addressed to him, but the return address said only “Anonymous Source.” The letter was postmarked June 28, the day of the shootings at the Annapolis newspaper.

When he saw the envelope, Hartley said, he called Norfolk police and did not open the letter.

The Pilot first reported the letter’s existence on its website Thursday evening and said that Norfolk police told one of its editors that they believe the letter is from Ramos.

The police took the letter to a lab, Hartley said, where they opened it and later told him what was inside: a CD and a greeting card. The card read something like, “Smile, you’re on camera. It’s your big day, and all eyes are on you,” Hartley said.

The Pilot reported that Norfolk police gave the letter to the FBI, which will transfer it to Anne Arundel County police, the agency investigating the shooting rampage. Norfolk police did not respond to requests seeking comment. An Anne Arundel police spokesperson said the letter is believed to be from Ramos, but authorities are attempting to confirm that. The Anne Arundel spokesperson declined to describe the letter’s contents.

Hartley said that police did not tell him what exactly was on the CD but said “there was nothing on it that was threatening or that I should otherwise be concerned by.”

A court-appointed attorney for Ramos and the Office of the Public Defender have previously said they could not comment on Ramos’s case because it is ongoing.

On Monday, three other letters police suspect Ramos mailed arrived at the law offices of a former Capital Gazette lawyer, at the offices of a Baltimore City judge and at the Maryland Court of Special Appeals.

The one sent to the law firm bore Ramos’s name and home address. It was a quasi-legal document that read in part: “I further certify I then did proceed to the office of respondent Capital-Gazette Communications . . . with the objective of killing every person present.”

Hartley’s column detailed how Ramos had harassed a former classmate from Arundel High School online, first through Facebook and then through emails. Ramos pleaded guilty in July 2011 to harassment and lost a defamation suit he brought against the paper over the column.

From late 2011 to early 2016, Ramos waged a social-media campaign against the Capital Gazette, its former editor Tom Marquardt and Hartley. His Twitter account mentioned Hartley’s name 101 times.

“I’ll enjoy seeing @capgaznews cease publication, but it would be nicer to see Hartley and Marquardt cease breathing,” said a tweet posted Feb. 2, 2015.

(This file has been updated with a statement from Anne Arundel County Police)