A shooting in Northeast D.C. early Saturday morning—one of several gun-related incidents over a bloody weekend—left a brother and sister dead in what appears to have started as a robbery attempt.

About 4:35 a.m. Saturday, the Metropolitan Police Department responded to a report of two people shot on the 5300 block of East Capitol Street NE. Detectives arriving on the scene found a man and a woman unresponsive and suffering from gunshot wounds. The man was identified as 21-year-old Jamahl Jenkins. He was pronounced dead at the scene.

The woman was identified as Jenkins’ sister, Jamie, 28. She was transported to a local hospital, where she later died of her wounds.

Police still have no information on any possible suspect, but the relatives say the double slaying started after an individual grabbed Jamie Jenkins’ purse, which contained a tablet computer and a phone, among other belongings. NBC 4 reports that after the robbery, Jamie Jenkins called her brother for assistance.

Both were later shot and killed, and police have not released many other details about the case, such as what transpired between the purse-snatching and the Jenkins’ deaths, or a description of any possible suspects. MPD is offering a reward of up to $25,000 for evidence or information that leads to a homicide conviction.

The Jenkins’ deaths were among several violent incidents in D.C. last weekend. About the same time they were shot, a man on the 1100 block of First Place NW was found with multiple gunshot wounds and pronounced dead at the scene, police said. The man’s identity has not been released.

About 11:30 p.m. on Friday, an adult male on the 200 block of K Street SW was shot in the back. And about 12:30 a.m. on Saturday, two males on the 2600 block of Birney Place SE were shot in their lower extremities, police said. Both suffered non-life-threatening injuries.

Jamie Jenkins was an aspiring singer fresh from a performance with a recently formed band, her family said. A vigil is being held tonight at 7:45 p.m. at a location still to be determined. Jamie and Jamahl Jenkins’ friends and family have also created a Facebook memorial page for the brother and sister.