Family and friends hold vigil for 17-year-old killed in the parking lot of a Northwest DC High School

The victim's grandmother, Sonia Ferrufino, said that being on the soccer field was sentimental because Jefferson Perez loved the sport.

"I want justice for my grandson," Ferrufino told WUSA9. She placed flowers on the ground of the parking lot where, according to the Metropolitan Police Department (MPD), the teenager was found with a single gunshot wound.

According to MPD, officers were called to Theodore Roosevelt High School in the 4300 block of 13th Street Northwest just before 2:30 p.m. Wednesday.

A school resource officer was on scene, but he was unable to stop the shooting, according to police. 

Investigators have yet to release any details regarding a suspect or suspects in this case. 

"I will not rest until they're arrested. This will not go unpunished," Ferrufino added. The mourning grandmother insists that the homicide is connected to a altercation last week, and that gangs are behind the deadly shooting. 

A Petworth neighbor who asked to remain anonymous told WUSA9 he was not surprised by the family's suspicions. 

"There is a gang problem in this area, there is a gang problem," he said. 

The longtime resident says he has informed both school and police officials about the growing number of gang-related fights off campus. 

"They're yelling out MS, 18 Street, watch out, they're going to come. They're going to kill you," he said. 

WUSA9's Delia Goncalves questioned DC Mayor Muriel Bowser about the alleged gang-activity in the area being reported by neighbors.

The mayor said, "I don't want to get ahead of police in the investigation, but I think they will have more to say about it."