The US law enforcement authorities were unaware of a series of hostile tweets against the Maryland-based Capital Gazette publishing house for more than two years by the man suspected of killing five people in its newsroom in the United States.

Police, however, had known that the suspect, Jarrod Ramos, had posted threatening comments on his web page about the newspaper, which he had unsuccessfully sued for defamation in 2012, according to a Reuters report.

“We were not aware of that history until last night. Should we have been? In a perfect world, sure, we should have been. We were not,” Anne Arundel County Police Chief Timothy Altomare conceded about the tweets at a briefing the day after the shooting at the Annapolis office of the Capital Gazette news group.

Ramos had accused one of the Capital Gazette’s newspapers, The Capital, of defamation for reporting on his guilty plea to a misdemeanor charge of harassing a female acquaintance online.

After his suit was rejected by the court in 2013, Capital Gazette attorneys and officials alerted police about “frank comments” online by Ramos directed at the newspaper and its journalists, Altomare told the briefing.

However, the publishing house decided not to proceed with harassment charges against Ramos during a 2013 conference call between Capital Gazette attorneys and police investigators, lawyers.

“There was a fear that doing so would exacerbate an already flammable situation,” Altomare said.

Ramos began by at least 2014 to post regularly on a Twitter account about his legal battle against The Capital, using a handle that incorporated the name of the reporter who wrote the story that triggered the failed defamation lawsuit.

The tweets on the account @EricHartleyFrnd referenced the battle against The Capital, its then-editor Thomas Marquardt and reporter Eric Hartley, who has since left the newspaper.

“Yes, Eric Thomas Hartley, you moved to ... oh just go ahead and kill yourself already before I do (legally in court),” read a tweet in 2014.

The account abruptly went silent in January 2016. But on Thursday, before the newsroom shooting began, a new post threatening the paper appeared in his tweet.

Ramos, who hails from Laurel, Maryland, faces five counts of first degree murder in Anne Arundel County criminal court.