In the episode, we learn that Libby's sister was the last family member to see the girl's alive.

INDIANAPOLIS (WTHR) — For the first time, we're hearing from the sister of Libby German nearly ten months after Libby and her best friend Abby Williams were murdered.

The Delphi mystery will be featured on Wednesday’s Dr. Phil.

In the episode, we learn that Libby's sister was the last family member to see the girls alive.

"When I dropped them off it was like any other time I dropped them off to go to the trail. I just said 'goodbye' and told Libby I loved her and said I'd see her when she got home," she said. "I miss having my secret keeper and my best friend."

Also in the episode, Libby's grandmother takes us inside Libby's bedroom.

"Everything is just as she left it. She had just painted her room. She said 'I could do it!' and she did. There's still a paint can from painting. Her stocking from Christmas last year right where it was."

In Wednesday's episode, you'll also hear from Indiana State Police Superintendent Doug Carter. He provides some insight into how that now-infamous suspect sketch was created.