In the images, mom Shanann Watts, 34, can be seen proudly snapping a photo of her 4-year-old daughter Bella, who's bouncing on a nearby trampoline, while the family was on vacation in Myrtle Beach, South Carolina, earlier this month.
Michele Greer met the family while they were standing in line waiting for the trampolines. She told Inside Edition that Chris Watts, 33, seemed indifferent to his family.
"He was just standing there," Greer said.
Less than two weeks later, the mom and daughters would be dead, allegedly strangled by Chris Watts. He faces nine charges, including several counts of first-degree murder.
Before he was arrested by police, Watts gave an emotional TV interview last week, pleading for his family's safe return when they were still missing.
They were found dead a day later.
Chris Watts has claimed it was Shanann Watts who killed the children after he asked for a separation, and he in turn strangled her in a rage, according to an arrest affidavit.
For Greer, the experience is surreal.
"She told me she was expecting and she was really hoping it was a boy," Greer said of the day she encountered the Watts family. "She kept touching her stomach. She was very excited that she was pregnant."
Chris Watts' next court appearance is scheduled for Nov. 19. He has not yet entered a plea.