The medical examiner said Willoughby was drowned after being stabbed. Court documents said blood tests from Ray's jacket matched hers.
Helen Frazier, Willoughby's mother, said in November her death was a tragic end to a relationship that was violent from the start. However, she said Willoughby believed she could make it work.
"When someone's heart is involved into something so deeply, trusted in a hope that things can be changed by love, then they're going to stay in that," Frazier said. "That's why she stayed in that relationship, in spite of what the end was going to bring."