Gwinnett police have arrested seven people following an investigation of an alleged gang-related fight involving nearly 20 teens earlier this year, Officer Jake Smith said Friday.

Gwinnett County Police Gangs Unit began the investigation two months ago with a report of gunshots at the fight in the parking lot of McDonald’s restaurant at 1881 Grayson Highway near Grayson, Smith said.

The fighters had vanished before officers arrived. Nobody was shot but a 911 caller reported an injured person, Smith said.

The officers found a “severely beaten” victim shortly later after a second report of another gunshot at a site nearby on Grayson Drive, Smith said. The injured teen had been beaten by the street gang “Ydubb,” Smith said. The group is believed to be a “hybrid gang” of the Young Wavy Goons — or YWG, Smith said.

YWG is known in Gwinnett because three members were convicted last October of murdering Paul Sampleton two years ago in a crime that shocked metro Atlanta, Smith said.

Sampleton, a 14-year-old Grayson High School student, was killed over his collection of valuable tennis shoes.

Sampleton was bound, shot and left to die in the kitchen of his townhome. Electronics and eight pairs of shoes were taken from the home. Police charged a 15-year-old classmate, Larnell Sillah, Sillah’s uncle Andrew Murray, 28, who prosecutors say was the triggerman, and Tauvaughn Saylor, 29.

All three received two life sentences, plus 120 years in prison after being convicted of murder, robbery and gang activity at their October trial.

After the January beating, the gang unit arrested seven suspected Ydubb gang members or affiliates believed responsible for the assault and charged them with aggravated assault, battery, and participation in criminal street gang.

Detectives found photos and online videos that showed the seven young men attacking people at random — even those with no gang affiliation.

The arrests of alleged gang members included two juveniles and five adults Rohshawn McKay, 20; Rashidi Allen, 17; Jahaud Jackson, 19; Alex Townsend, 17; and Jourdan Stanton, 19.