A group of cybersleuths have tracked down two men who allegedly attacked police officer Jeffrey Smith at the US Capitol during the 6 January insurrection, leaving him with injuries that have been linked to his death days later.

In a new complaint, attorney David P Weber – who represents Smith’s widow, Erin – wrote that David Walls-Kaufman and and Taylor F Taranto appeared to specifically target Smith because his eyes and face were vulnerable.

The lawsuit said Walls-Kaufman used a cane, crowbar or similar object to level a brain injury to Smith, who took his own life on 15 January. Jonathan Arden, DC’s former chief medical examiner, has attributed Smith’s death to post-concussion syndrome, which can lead to symptoms like depression and suicidal thoughts.

About a dozen people with the open-source intelligence group Deep State Dogs pored over evidence from the capitol attack for more than a month until they found footage of Smith and his assailants.

“We felt we had to do something to honor the memory and family of Officer Smith. It’s terrible that the bereaved were left in that situation,” Forrest Rogers from Deep State Dogs told HuffPost. “So we turned to the thing we do best: finding bad guys.”

Walls-Kaufman, a chiropractor, has said in the past that about 40% of his clients work at or around the Capitol. In January, he was quoted in a story about the riot, which implied he was in attendance.

Taranto – a US navy veteran from Washington state – handed a weapon to Kaufman, who then struck Smith in the head. The battery led to a concussion, according to the lawsuit.

“But for the concussion of Officer Smith at the hands of these defendants, Officer Smith would be alive today,” Weber wrote.

Smith’s widow, Erin, has been trying to convince the Police and Firefighters’ Retirement and Relief Board to consider her husband as having died in the line of duty. But the DC metropolitan police department has refused to release Smith’s body-camera video showing what actually happened, and Weber expressed frustration about how little federal law enforcement has done to avenge Smith months after the attack.

“I thought the I in FBI stood for ‘investigation’,” Weber told HuffPost. “It’s pretty lame that a private lawyer for a dead police officer’s widow has to be the one conducting the investigation.

“The fact that these volunteers have accomplished what the FBI has not is extraordinary.”