Nineteen-year-old Tommie Lou Whiddon was sunbathing on a bright March day in Florida when a fledgling serial killer pounced on her.

As the junior college student lay helpless and alone in her bikini, 17-year-old Frank Athen Walls slit Whiddon's throat on Okaloosa Island on March 26, 1985. He left her to bleed to death and disappeared without anyone having witnessed the murder.

During the following two years, Walls would go on to kill at least four more people − all before he turned 20. Two of the other victims were mothers, one was a new grandma, and one was an Air Force Airman who died trying to protect his young girlfriend. Because all of them were killed either on a Tuesday or before dawn on a Wednesday, police dubbed the case "the Tuesday murders."

Now 40 years later, Florida is set to execute Walls by lethal injection on Thursday, Dec. 18. That will make him a record 19th inmate executed in the state this year and the 47th in the nation, a number not seen since 2009.

Though many family members of the victims have died waiting for justice, those who are living hope that Walls' death will bring some relief.