The Johnston Gang operated on one simple principle: Don't snitch on the family. People who did found out the hard way how far the Johnstons would go to keep their crimes secret. In August 1978, the family's criminal empire came crumbling down when their threats and intimidation turned to murder. The Killing Month August 1978 is the true story of a rural crime family that would stop at nothing to keep people quiet—even their own children.

In late August 1978, two men hid in a cornfield in Chester County, Pennsylvania. They were waiting for 15-year-old Robin Miller and her boyfriend Bruce Johnston, Jr. When the couple arrived, the ambush began. This brazen, murderous attack crossed a line. The leaders of the Johnston Gang didn’t know it yet, but their family crime empire began to crumble that night.

Six years before the murders of August 1978, two police officers were ambushed and gunned down in the sleepy town of Kennett Square, Pennsylvania. Though Bruce, David and Norman Johnston were not charged at the time, investigators always knew there was a connection to The Johnston Gang. Years later, they would trace a line back to the Kennett Square murders as the starting point of a reign of terror that claimed at least six lives.

The first rule of running with The Johnston Gang: You don’t snitch. In July 1977, Gary Crouch learned that the hard way. One day he was a police informant, helping to build a case against Bruce, David and Norman Johnston. The next...he was gone. To figure out what happened to Gary, the police will have to find another member of the gang willing to put his life on the line.

When teenage members of the gang disappear, investigators know the clock is ticking. Once again they rely on a Johnston Gang snitch to lead them to answers. On a cold December night, in a remote, wooded area of rural Pennsylvania, police start to dig. What they find makes it clear the Johnstons will stop at nothing to keep people from ratting on the family.

As a burglar who ran with The Johnston Gang, James “Disco” Griffin saw firsthand how ruthless Bruce, David and Norman Johnston could be. But Griffin was no killer, and he was desperate to get away from the gang before he had blood on his hands.

If the family is willing to kill to keep people quiet, how will Griffin get out of the Johnston Gang alive?

After years of ruthless violence and criminal activity, David and Norman Johnston are charged with multiple counts of murder. In a Pennsylvania courtroom 225 miles away from Chester County, they face a jury. Will the testimony of snitches be enough to convict them?

Since the murders of two Kennett Square police officers in 1972, investigators have been building the case against Bruce Johnston, Sr. In March 1980, justice finally came for the leader of the family crime empire. As prosecutor Bill Lamb told the press after the verdict, “The wheels of the justice system grind slowly, but they do grind.”