Kent Lewis was going about his day a while ago when he came up the escalator at the Rosslyn Metro station.

He was shocked when he saw the person panhandling at the exit to the station: his brother, Richard.

Lewis tried that day and on many other occasions to get his brother to stop panhandling, to sleep somewhere safe at night, to take the medications that kept his schizophrenia under control.

But in the early morning of Oct. 2, Richard Lewis was outside a Metro station again, this time Union Station. Someone attacked him there, kicking him in the head over and over until he passed out.

He never regained consciousness. On Jan. 6, Lewis died at age 57, becoming the first homicide victim in the District in 2017.

Richard Lewis (Courtesy of Kent Lewis)

Now Kent Lewis. who lives in Ashburn, Va., is trying to do one last thing for his brother, after decades of struggling to watch out for Richard: to find someone who can identify the man who killed him.

D.C. police posted a video, about a minute long, of a man they say is a person of interest in the case. Since Monday, 1,800 people have watched the security camera footage of the man pacing outside Union Station, smoking a cigarette. Kent Lewis wants the video to reach far more people, in the hope that one of them knows who the man is.

“He was a good guy. He was a smart guy. He unfortunately fell prey to this illness,” Kent said of Richard’s schizophrenia. “This illness led to him being taken advantage of by the people in his world.”

Richard Lewis’s life started out drastically different from what it eventually became, his brother said. Their mother was raised in Mexico and their father was American, and they grew up mostly in Mexico and Colombia. They lived well there — maids, guards, a chauffeur.

Then both brothers decided to enlist in the U.S. military. But when Richard entered Marine boot camp, it quickly became clear that something was wrong.

He was discharged after he was diagnosed with schizophrenia, Kent said.

When Kent moved to the District to study at George Washington University in the late 1980s, Richard followed, and lived with his brother for a time. For a while, Kent said, Richard did well. He found work as a night watchman, and stayed on medications that kept his mental illness under control.

He lost that balance after their mother died in 2002, and he never found stability again, Kent said.

Without the right dosing, Richard was delusional, paranoid and prone to hearing voices. When Richard was taken into psychiatric units, often after being picked up by the police, Kent often thought that doctors released his brother too soon, before he was stable.

“I was always very concerned, in releasing him, that he would get in trouble. He would yell at people,” Kent said.

Indeed, Richard was beaten and robbed numerous times over the years. In one particularly troubling episode, Richard became agitated and angry at a woman near Eastern Market, one of his favorite places to hang out. He called her the n-word. A group of men came to the woman’s defense, and Richard never frequented Eastern Market again.

Kent said Richard would lash out at family members too, then apologize for his bad behavior as soon as he was back on his medication.

“It’s a tough thing, as a relative. To experience this and then to sustain a relationship is a challenge,” he said. “In my case, I was working as best I could, trying to understand and deal with what was going on with him, and seeing him deteriorate. It was tough.”

Richard became homeless for a time, then got a subsidized apartment through Pathways to Housing D.C., which operates on the “housing first” principle that people should not have to try to take care of issues like mental illness until they have a roof over their head first.

Kent called Richard’s caseworkers at Pathways “saints” who worked with him for years — most recently, he was trying to get a government-issued ID so that he could apply for jobs again.

But even with that help, it was hard to get Richard to go home. In his paranoia, he sometimes believed residents of his new street would attack him, and he would sleep on park benches or wander the streets instead of going to his apartment on those nights.

Kent assumes that is what Richard was doing about 2:30 a.m. Oct. 2, when a Maryland woman called police to say she saw someone kicking Richard repeatedly in the head in the passenger drop-off area in front of Union Station.

The police report said the suspect walked north on First Street NE after the attack. Police posted the video of the person of interest, but didn’t provide information to The Washington Post about whether they have received any tips on who the man might be.

Kent hopes one more person might help him look out for his brother in death, as many did in life.

Like the staff at Pho 75, an Arlington shop where the brothers have been dropping in for Vietnamese soup since the late ’80s. Sometimes Kent went there and left some money at the counter to pay for Richard’s next meal.

That way, when Richard would stop in for a bowl of hot soup, someone would take care of him.

Peter Hermann contributed to this report.