Police have named a suspect in a double homicide in Columbia Heights.

Wanted posters hanging in the neighborhood show the face of Irving Harris Johnson, 25, who police say is the lone suspect in the shootings of Jimmie Lee Simmons III, 32, and Dominique Barber, 31, of Northwest. They were killed in the 1400 block of Parkwood Place on July 9.

Barber, Simmons and a third man were shot in the head shortly before 6 a.m. outside a house that neighbors and D.C. Council member Jim Graham (D-Ward 1) say is notorious for late-night drug-dealing and gambling. The third man is still being treated for his injuries, Graham said Tuesday.

Community members expressed concern about what they say is increased violence in the area this summer. The Parkwood Place incident is part of a recent spate of violence that includes two shootings on Spring Road and an armed robbery nearby.

“We feel like there’s more of it happening and it’s becoming more violent,” said Lisa Kralovic, an Advisory Neighborhood Commission member who represents the area where the killings took place. “What’s most discouraging to me is police seem to be in the area, yet this is still happening.”

Irving Harris Johnson is wanted in connection with the homicides of Dominique Barbour and Jimmie Simmons which occurred on July 9, 2011. (Courtesy of MPDC)

After the July shootings, police said they planned to increase their presence in Columbia Heights. At least two officers patrol the 14th Street corridor on foot during each shift, Graham said, and others patrol the area in cars.

Johnson is a known “bad player” in the neighborhood, Graham said. He was sentenced to 14 months in prison in 2009 on gun charges,court records show, and 16 months for drug charges in 2006. Police did not discuss a potential motive for the July shootings.

In a press release Monday, police described Johnson as a black male with a medium complexion and a lazy left eye who stands 5 feet 10 inches tall and weighs about 160 pounds.

Graham praised police for turning to the public to track him down.

“It’s unusual for them to launch a poster with a name and photograph,” Graham said. “I think it shows a level of aggressiveness that they shouldn’t let up.”

Gwen Crump, a D.C. police spokeswoman, said the decision to release information about suspects is made on a case-by-case basis.

Staff writer Keith L. Alexander contributed to this report.