There is not much info on this case, except the one from the great job done by the Cold Case Database.
"On Aug 10, 1976, Helen Whitlock found the badly decomposed bodies of Hazel Juanita Hanna and Cynthia Lorraine Bell on her farm near the Cedar-Polk county line. The girls’s hands were tied up with a belt, partly undressed, and both shot dead.
Helen Whitlock told police that on the evening of Aug 4, around 10.15 pm, she was cleaning up in her home. She heard four gunshots within a time frame of about 30-60 seconds. Her husband, Frank, was outside tending to the cows. He was just moving his trucks when in the distance, he heard a girl laugh. Then about 15 minutes later, he heard gunshots. He also heard four shots but places the time frame closer to 1-2 minutes.
Frank finished his chores. Then he took his shotgun and got into his truck. He drove around his farm and saw a car parked in a hayfield in a brushy area near his gate. It is in this area that much later Hazel and Cynthia were found dead. When he saw the car he thought it was just another groups of partying teens as the area was known for that. He continued driving, returned to that spot, but then the car was gone."
On this link from the Cold Case Database there is more detailed info: Hazel Juanita Hanna and Cynthia Lorraine Bell - Defrosting Cold Cases
"On Aug 10, 1976, Helen Whitlock found the badly decomposed bodies of Hazel Juanita Hanna and Cynthia Lorraine Bell on her farm near the Cedar-Polk county line. The girls’s hands were tied up with a belt, partly undressed, and both shot dead.
Helen Whitlock told police that on the evening of Aug 4, around 10.15 pm, she was cleaning up in her home. She heard four gunshots within a time frame of about 30-60 seconds. Her husband, Frank, was outside tending to the cows. He was just moving his trucks when in the distance, he heard a girl laugh. Then about 15 minutes later, he heard gunshots. He also heard four shots but places the time frame closer to 1-2 minutes.
Frank finished his chores. Then he took his shotgun and got into his truck. He drove around his farm and saw a car parked in a hayfield in a brushy area near his gate. It is in this area that much later Hazel and Cynthia were found dead. When he saw the car he thought it was just another groups of partying teens as the area was known for that. He continued driving, returned to that spot, but then the car was gone."
On this link from the Cold Case Database there is more detailed info: Hazel Juanita Hanna and Cynthia Lorraine Bell - Defrosting Cold Cases