A YOUNG FAMILY IS IN A NASTY CUSTODY DISPUTE AND THE FATHER IS MURDERED -- CAN A POTTED PLANT AT THE SCENE HELP SOLVE THE CASE? "48 HOURS MYSTERY," SATURDAY, FEB. 10

Jarrod Davidson and Kelee Jones were college sweethearts. Within a year of meeting in chemistry class, they were moving in together, having a first baby, and planning a wedding. But the seemingly happy relationship ended in a bitter divorce and a nasty custody battle over the couple's daughter. On a July night in 2004, Jarrod was shot to death outside his Santa Barbara, Calif. apartment complex. Correspondent Maureen Maher follows the story as sheriff's deputies unravel a plot so bizarre that it puts three members of one family in prison - all in connection with a single murder. 48 HOURS MYSTERY: "Murder Comes Knocking" will be broadcast Saturday, Feb. 10 (10:00-11:00 PM, ET/PT) on the CBS Television Network.

From the beginning, there was trouble in the Davidson marriage. However, they always had their tremendous love for their daughter, Malia, in common. When the couple divorced, Kelee was granted custody and Jarrod visitation. Kelee made visitation for her ex-husband extremely difficult and her disrespect for Jarrod's court-ordered rights was starting to put her own custody rights at risk.

"There were numerous occasions when he had gone to try to pick up his child at her residence and was denied access to the child," said Santa Barbara sheriff's detective Greg Sorenson.

When Sorenson was called to Jarrod's apartment the night he was shot, he knew instinctively that Jarrod's ex-wife might be involved. What Sorenson could not predict at the time was who else may have been involved in this murder plot, who actually pulled the trigger and who was possibly "pulling the strings."

Something struck Sorenson as very odd at the murder scene: a potted plant with the words "To My Teacher" written on a card. Jarrod was a part-time teacher and now Sorenson strongly suspected that the killer knew Jarrod or personal things about him.

The plant was a clue but it wasn't until five months later that a state crime lab got a hit for female DNA on the plant's card holder. Sorensen began building his case against Kelee -- learning more about her and her incredibly close relationship with her parents, Mindy and Phil Jones. The Joneses, it would turn out, would do anything to keep custody of little Malia for Kelee - and themselves.

Detective Sorensen was shocked when the DNA came back - it wasn't Kelee's, but her mother's. The Joneses had told sheriff's deputies they were on a beach 90 miles away from Jarrod's apartment on the night of the murder. But their cell phone records and cell tower information with coordinates told a different story.

All three, Mindy, Phil and Kelee, now sit in prison in connection with the death of Jarrod Davidson. One of the Joneses confessed in open court to pulling the trigger and another claims a case of complete amnesia. But which member of the family now says he or she lied in court about what happened just to get a plea deal?

48 HOURS unravels a family conspiracy and reveals an exclusive interview with the person who admittedly shot Jarrod. The question remains: what pushed the Jones family to think that murder was the only answer?

48 HOURS MYSTERY: "Murder Comes Knocking" is produced by Ira J. Sutow. The associate producer is Elisabeth Harris. The senior producer is Judy Tygard. The executive editor is Al Briganti and the executive producer is Susan Zirinsky.