Barron Goodwin moved in with his in-laws in November after his partner died of liver failure. The 60-year-old suffered from dementia, and he often sat on the black leather couch under the front window of the rowhouse in Southeast Washington.

A few minutes after 11 a.m. on Wednesday, a bullet fired outside went through the window frame, pierced a curtain and struck Goodwin in the back of the head. He tumbled to the carpeted floor, where his brother-in-law found him after rushing down the stairs.

Goodwin died at a hospital more than four hours later, the District’s 19th homicide victim of 2020.

D.C. police have not made any arrests and are investigating the daylight gunfire in the 800 block of 51st Street SE in the Benning Park neighborhood. Another bullet went through the front door and struck a staircase. Two more struck vehicles parked along the curb.

Relatives believe a stray bullet took Goodwin’s life. Police said the case remains open, and a department spokesman said the possibility of an errant round is part of the investigation. Authorities had no description of a gunman and were urging neighbors with surveillance cameras to contact investigators.

“We’re way past angry,” said Goodwin’s sister-in-law, Carolyn Groce, 55. “We want this taken care of. . . . I want the police to figure this crime out and solve it. I know a lot go unsolved, but this is unacceptable.”

On Thursday, Groce, a security guard at the National Gallery of Art, sat on the same couch on which Goodwin had been shot, although she avoided the middle cushion, the one under the window. She paged through photo albums of his marriage in 2011 to her brother, Herbert W. Windear.

“They definitely loved each other,” Groce recalled.

The two had met 11 years ago. Windear was a cook at several schools in the District; Goodwin was a security guard at one of the big office buildings along K Street in Northwest. They shared an apartment in Southeast.

For a while, Goodwin took care of Windear as his liver failed. But Goodwin’s dementia got worse, and when Windear died in November at age 52, Groce said her brother-in-law didn’t know he was at a funeral.

Goodwin moved in with Carolyn Groce and her husband, Harry Groce, 61, who also works as a security guard.

Along with their 20-year-old daughter, Indya, they helped Goodwin bathe, took him to doctors and to church socials, and out for seafood, one of his favorite foods. He had an affinity for music, and could recognize songs that Harry Groce played.

He listened to go-go, rhythm-and-blues and “old-school 70s.” “You play a record, and he would say, ‘Oh, I know this song,’ ” Harry Groce said.

And he loved to dance.

“Take him anywhere, and he went dancing,” Harry Groce said, as his wife pulled out a picture of Indya pairing off with Goodwin just a few months ago. On his better days, Goodwin helped with the cooking or anything else the family needed.

Goodwin grew up in South Carolina, where his mother lives, though she could not be reached. The Groces said he had no other family in or around the District.

Carolyn Groce described Goodwin as an “easygoing, get-along, go-along guy who was always happy.”