Judith Grayson is the friend of murder victim Ruth Thomas. Hoping to find her a man after Ruth’s husband died, Judith encouraged her to date serial romance scam artist Lyle Christopher, but Christopher kept living off her money. When Ruth threatened to sue Christopher and report him to police, Christopher killed her and disappeared her remains out at sea on a boat.
When detectives informed Judith, she was horrified and knew for a fact Christopher killed Ruth, telling the detectives of the ultimatum Ruth left Christopher with before she was murdered. Judith gave her testimony to the point she directly accused Christopher on the stand, which had to be stricken from the record. The prosecution redirected by having Judith emphasize when Ruth was once reported missing on a fluke, it was when she went to the Bahamas by plane, not boat.
Christopher wasn’t convicted when the first trial ended in a mistrial, only on the second one when a fisherman found Ruth dead. (L&O: "Corpus Delicti")