21-year-old Shontae Peterson had been dating 24-year-old Carnell Parker for nearly a year.
On Saturday night July 5, 2008, Carnell had gone out with family and friends.
Peterson stayed behind at Carnell's house in the 200 block of Charles Street in Coatesville.
Carnell returned home early the next morning alone.
Police say sometime after 2:30 a.m., both Carnell and Peterson were shot execution style inside the home.
Carnell's younger sister was also in the home at the time of the shooting, but she was unharmed.
Now 5-years later, their families want justice.
"The family would like to solve this crime. They need to find some type of closure and find out why this happened," said Santo Montecalvo, Citizens Crime Commission.
The hope is that a $10,000 reward will entice someone to come forward.
"You wouldn't want that to happen to your brother or your sister. You need somebody to pick up the phone anonymously and call the tipline 215-546-TIPS and give us the information," said Montecalvo.
The reward is for information that leads to the arrest and conviction of the person responsible.
Anyone with information on this or other crimes can call 215-546-TIPS (8477).