On the evening of October 23, 2014, Douglas and Deborah London of York County, South Carolina—just across the border from North Carolina—were watching television in their home when the doorbell rang. When they opened the door, she was immediately shot in the head by a man standing outside, and her husband was shot multiple times. Their adult son, who was also present, made a frantic call to 911, but the couple died next to each other on the floor of their home.

As the York County Sheriff’s Office began to investigate the double homicide, they asked the FBI’s Charlotte Field Office for help.

In the coming months, the investigative team of FBI special agents and task force officers from the Charlotte-Mecklenburg Police Department uncovered a web of violence that stretched across state lines and beyond local prison cells.

Turned out that the Londons had been specifically targeted—they were the owners of a mattress store in Pineville, North Carolina that had been robbed at gunpoint by three men five months earlier. Jamell Cureton, the leader of the Valentine Bloods—a hood, or set, of the national and exceedingly violent United Blood Nation (UBN) gang—had gone into the store and pulled his gun on Douglas London, who had his own gun. The two exchanged gunfire, and Cureton was hit. Also at the scene that day were Nana Adoma, the lookout who was just inside the door; and David Fudge, the getaway driver in the car outside.

The three escaped and drove Cureton to a hospital, but all three were taken into custody shortly afterward by local police and faced state charges.

Realizing that Douglas London was the only eyewitness who could identify him in the mattress store robbery, Cureton—who was in state custody at the time—discussed the“elimination” of London with other gang members through a series of phone calls, letters, and in-person visits.

Valentine Bloods member Malcolm Hartley was to be the triggerman. He was driven to the Londons’ home by fellow gang member Briana Johnson, rang the couple’s doorbell, and murdered them both in cold blood. “And then,” said FBI Special Agent Chad Pupillo, “Johnson drove him back to Charlotte, where they met with other gang members, disposed of the evidence—including burying the murder weapon—and celebrated the victims’ murders.”

After the killings, Cureton sent a letter from jail to a confidant explaining that he had ordered the murder of Douglas London and described Deborah London as “collateral damage.” He also ordered the gang to remain silent about the murders and authorized action—i.e., violence—against anyone who talked about them.

The joint federal/local investigation into the murder of the Londons and the criminal activities of the Valentine Bloods was complex and involved search warrants for residences, social media accounts, phones, and prison cells as well as subpoenas for financial records, phone records, jail visitation records, and mail. Explained Pupillo, “The Londons’ murders, which received a great deal of media coverage, were particularly alarming to members of the public. We had to identity these violent criminals and get them off the streets as quickly as possible.”

One vital discovery by the investigators was the gun used to kill Douglas and Deborah London—it was located and dug out of the ground by the Bureau’s Evidence Response Team and other FBI Charlotte personnel in a wooded area not far from a gang member’s residence.

During the investigation, law enforcement was also able to collect enough evidence to solve another Bloods-related murder—this one from 2013 involving a teenage boy who falsely claimed to be a member of the gang. This, apparently, was an executable offense, so Cureton ordered the killing. The young man was then lured to a public park and shot by Adoma and fellow gang member Ahkeem McDonald, who was also subsequently linked to the London murders.

A total of 12 individuals were charged federally in a racketeering conspiracy centered on the murders. All have been convicted at trial or pleaded guilty, and six of the defendants have received life without parole—including Cureton and Hartley—while the remaining defendants have received sentences ranging from 13 to 30 years in prison.

“Getting justice for the family of this teenager and for the family of Douglas and Deborah London was a primary motivator for investigators in this case,” said Charlotte-Mecklenburg Police Detective Michael Sardelis, “as well as a desire to protect the public from the violence and other criminal acts perpetrated by these gang members.”

And they won’t be slowing down their efforts anytime soon. “At the same time the FBI and its partners were working on this case,” Pupillo said, “we were also working on a much larger six-year investigation involving another UBN hood that resulted in the indictment of 83 gang members.”