Did Siblings Murder the Man Who Loved Them?

June 24, 2009— -- Tim MacNeil was a successful defense attorney who got along with everyone and had no enemies, according to those close with him.

But two years ago, he was gunned down by a masked intruder in his San Diego home - the only eye-witness: his seventeen-year-old stepdaughter, Brae.

It seemed at first like a random home robbery gone bad, but evidence soon began to point to his two stepchildren, Brae and 19-year-old Nathan. Both are charged with the murder but who really did it?

With one trial, the unique situation of two separate juries, and both siblings pointing the finger at each other, could they both get off? Mary Fulginiti unravels the case with exclusive interviews with Brae and Nathan, a startling jailhouse confession, and cameras in the courtroom, on the premiere of "Primetime: Crime," airing Wednesday, July 1 at 10 pm ET.

According to Brae, a man dressed in black burst into their home in broad daylight and asked for the combination to her stepfather's safe. When Tim refused, the masked intruder shot him and ran out the back door. Brae was spared, and left with her hands zip-tied behind her back.

She told police she dialed 911 with her tongue. While being questioned, however, Brae seemed to slip by revealing she heard her stepdad ask: "Why are you doing this Nathan?" Authorities began to question Brae's story and ask themselves whether MacNeil's' stepson or daughter could be the killer.

What could cause these young people to murder the man who showed them so much acceptance and love? Fulginiti interviews both Brae and Nathan to get deep into the psychological motives behind this crime.

Tim entered their lives when he married their mom, Doreen. Brae and Nathan's were just five and seven years old, respectively, and according to relatives, he treated them like his own children.

But Fulginiti reports that their mother had become deeply depressed and emotionally abusive to Nathan and Brae from an early age and Tim was often the one to protect them. Brae and Nathan spent their lives trying to earn their mother's love but she ultimately made good on years of threats to kill herself. Her suicide would prove the catalyst that set a murder in motion.

But would the jury-members be able to figure out who really committed the crime?

Because some evidence is not admissible for both defendants, the trial is conducted with two separate juries -- a rare legal scenario that presents the possibility of both defendants getting off. With cameras in the courtroom, "Primetime" is there every step of the way, even exposing a confession that neither jury ever gets to hear.