July 1, 2009 -- On July 19 2007, 63-year-old San Diego defense attorney Timothy MacNeil was murdered in broad daylight in the house he shared with his 17-year-old stepdaughter Brae Hansen. Police initially thought it was a robbery gone bad.
Cops who arrived at the scene found MacNeil dead from gunshot wounds to various parts of his body. There seemed to be no signs of a forced entry, and the contents of the family safe were intact. But blood spatter and bullet holes lodged in the wall told the tale of a violent struggle.
Officers found Brae cringing in a corner of the room where MacNeil's body lay. The 17-year-old was visibly shaken. Her hands were crudely bound together with plastic zip ties. She explained to police that she had managed to call 911 by using her tongue.
Watch the full story on "Primetime Crime" TONIGHT at 10 p.m. ET.
Brae gave police a statement in which she described the intruder's height and said he was wearing all black. But she said she didn't see his face, which was covered in a black mask with eyehole cutouts. (Click here to watch Brae under questioning).
A few elements of Brae's story struck veteran Detective J.C. Smith as odd -- but one in particular stood out.
"...To be killed...in your own house is a very, a very brutal, violent killing, and to leave a witness to that seemed unusual," Smith told ABC News.
After Brae gave her statement, she was released and sent to the home of MacNeil's brother and sister-in-law. The couple soon sensed something wasn't right; their instincts proved correct.
In a statement given later that evening to another detective, Brae said that MacNeil had called the killer "Nathan" -- the name of her 20-year-old brother, who was away at college in Arizona. Brae quickly backtracked, tried to deny she said it, and then went out of her way to clarify that the killer definitely wasn't her brother.
This change of story, along with other inconsistencies, led police to arrest both Brae and her brother Nathan, who had been living with his grandmother in Arizona.
Police read Brae Hansen her rights that evening and turned on a video camera in the interrogation room. She began to recount an astonishing tale.
"Do you think you should be charged with anything?" asked Smith on the tape.
CLICK HERE to see photos of Brae and Nathan through the years.
Stunning Confession: 'I Wished I Could...Kill My Dad'
"I did kind of start the whole thing," replied Brae. "Even if it was -- I don't know -- a lapse of judgment or whatever ... I mentioned to one of my friends, Nicky, that, like, I wished I could ... like, kill my dad or whatever."
The detectives were stunned. "I still can't believe I did this," Brae said, crying. "It's not like me."
Brae admitted to cops that she called Nathan because she was upset at her stepfather. Brae told police, and ABC News in an interview with Mary Fulginiti, that she placed a spare key, a gun that once belonged to her mother and cash in a box on the back patio of the house for Nathan to access so he could commit the murder.
Brae said that the money was originally supposed to pay for a hit man who would make the killing look like a deadly burglary, but that plan fell through. Brae said she decided she didn't want to go through with the arrangement -- but then, the night before the murder, she said Nathan showed up in Brae's bedroom dressed all in black.
"This is going to happen whether or not you want it," Nathan allegedly said to Brae as he brandished a gun in her face. "And if you're smart you'll go along with it, or you'll end up just like him."
So Brae said she did just that. When MacNeil came home July 19, 2007, from a night spent at his girlfriend's, he was attacked by the siblings, according to Brae. She said she bound her stepfather's wrists with zip ties, and then Nathan zip tied Brae's wrists. It was Nathan, Brae claimed, who shot MacNeil four times, bolted out the back door, jumped in his truck and drove back to Arizona.
But what was Nathan's side of the story? He said he wasn't even in California that day, let alone at the scene of the crime.
In a videotaped interrogation with San Diego detectives J.C. Smith and Brett Burkett, Nathan denied any involvement, and then asked to speak to an attorney.
"I need a lawyer," Nathan said. "This is too powerful ... I'm trying to tell you guys I wasn't involved."
Dark Family History Drives Murder
Nathan and Brae seemed like the kids next door-- but as police delved into their backgrounds, they learned that deep beneath the surface lurked a horrible family secret.
Their mother, school teacher Doreen Hansen, had been suicidal and depressed for years. And according to many, her illness manifested itself as acute emotional, verbal and even physical abuse of Nathan and Brae.
Amid the terror of the abuse, MacNeil, who married Doreen when the kids were 4 and 6 years old, was a source of solace for the children. He was the one they felt they could trust.
In the summer of 2006, tragedy struck when Doreen MacNeil committed suicide by swallowing a bottle of pills. After Doreen's death, Nathan stayed in Arizona but Brae moved back in with MacNeil. A year later, Brae and her brother were charged with MacNeil's vicious murder -- tragically, one day after his 63rd birthday.
Siblings Stand Trial with Separate Juries for Murder
Two years after the crime, in March 2009, the siblings stood trial for the murder of their stepfather. Pointing fingers at each other, Brae and Nathan were set to be tried at the same time but with two different juries -- a rare legal tactic designed to expedite the trials while keeping damning evidence from one case tainting the other's jury. Brae's jury would hear her confession, but Nathan's jury would not, because it was ruled inadmissible in his case.
Before the proceedings began, the prosecution suffered an astounding blow in pre-trial hearings when a judge ruled that Nathan's confession was inadmissible because of a Miranda issue. Jurors would never hear his confession.
For the prosecution and the police, the stakes were extremely high because this wasn't the first time the case had been presented. In November 2008, Nathan went on trial for the crime by himself, but the case was declared a mistrial because of a hung jury.
In his opening statement March 23, 2009, veteran prosecutor George Bennett made sure he painted a vivid picture for the jury.
"[MacNeil] had been shot 4 times. Once in the side, once in the face, in the head with grazing wound, and then shot point blank range in the back of his head ... What the evidence shows, ladies and gentlemen, in this case, is that a conspiracy to kill Timothy MacNeil existed between Brae Hansen and her brother."
Brae's defense attorney Troy Britt told another story.
"[Brae] tried everything she could to stop her brother Nathan Gann from killing their father Timothy MacNeil," he said in his opening.
And Ricardo Garcia, Nathan's attorney, had yet another version of the crime -- one in which Nathan played no part at all.
"[Brae] confided in friends that she wanted to have her stepfather killed and wanted him dead," Garcia argued. "At the end of this you'll realize that Nathaniel Gann did not shoot and kill Timothy MacNeil ... he had no motive, no reason."
Brae's jury heard Brae's entire riveting confession, in which her demeanor on the grainy interrogation room video ranged from scared little girl to cavalier and even at times, flirtatious.
Nathan's jury, on the other hand, heard a circumstantial case based mostly on physical evidence -- and Nathan's defense attorney managed to poke holes in much of the prosecution's theory.
Possible Motive Emerges: Jealousy
While at first it seemed there was no good motive for the murder, one possible reason did emerge -- jealousy.
Brae had become used to having MacNeil all to herself. But MacNeil had recently fallen in love with a woman named Kim. In her confession, Brae admitted that she wasn't happy about this development.
"He was basically going to cut me out of his life completely," she said in the videotaped statement. "I knew he'd already chosen his girlfriend over me and it hurt really, really bad because this was the man I thought loved me, and was my dad."
When MacNeil asked her to move out, Brae said they had a horrible fight that prompted her to make the phone call to Nathan that would set everything in motion.
"I basically ask him to calm me down," Brae told Fulginiti about the call. "...Instead, he said, 'Well, ya know, what if he weren't there anymore?' And I was like, 'Well, ya know, that would be ... kinda cool.'
"I was very hurt, I was very angry," Brae continued. I wanted [MacNeil] to hurt like he had hurt me."
In closing arguments at the trial, prosecutor Bennett posited that Nathan was the killer, but he had the harshest words for Brae.
"...This is a monstrous crime," he told the jury. "She never tried to withdraw from any conspiracy, it just got messy ... And the only reason that [MacNeil] ended up like that is because of her and because of her brother."
He pointed to Brae, crying at the defense table. "And those tears, and that expression is too late!"
In their closings to two separate juries, Brae and Nathan's defense attorneys did a thorough job of fingerpointing, each singling out the other's client as the main perpetrator.
Everyone waited while the juries deliberated. Would they convict one sibling and let the other go free? Could they acquit both defendants? Would there be another mistrial?
A Second Confession: Nathan Recounts Murder
For the police, the wait was even harder to endure because they knew something the juries would never know: the night after the murder, Nathan had actually confessed to being MacNeil's killer.
After Nathan asked police for a lawyer during his interrogation, Detectives Smith and Burkett got up to leave the room but Nathan unexpectedly called them back, saying he would waive his rights. What followed was a chilling step-by-step recounting of a murder.
He described the struggle with MacNeil and the gun, and even volunteered to act out the killing for the detectives.
"Did you feel like you had to shoot him?" asked Smith on the tape.
"Yeah," Nathan replied. "Well, after he was dying ... so he doesn't sit there and bleed to death."
A jittery-looking Nathan also gave a glimpse as to why he might have wanted to kill MacNeil.
"I wanted him to honestly feel like -- take me seriously for a change. He just ... dismissed me," Nathan told the detectives.
But because of legal issues surrounding Nathan's Miranda rights, the confession was ruled inadmissible, meaning neither jury got to hear it.
Verdicts Arouse Deep Emotions, Remorse
After three days, the juries returned.
Nathan Gann was found guilty of first degree murder. But in a small victory for his defense, Nathan's jury decided that there was not enough evidence to prove that it was Nathan who pulled the trigger. He received a sentence of 25 years.
Brae Hansen was found guilty not only of first degree murder, but also of a gun charge and a special circumstance of "lying in wait." She was sentenced to life without parole.
Jurors told ABC News they were unanimous. For the MacNeils, the verdicts provided closure and a sense of justice served, but Timothy MacNeil's daughter Erin Ellison found she was still wrestling with her emotions about Brae.
"I mean ... I haven't even hugged her," Ellison said tearily to Fulginiti. "...I just wanted to go and just tell her ... I'll miss you, I'm mourning you, I'm mourning the loss of you as much as I'm mourning the loss of my dad..."
Brae told ABC News that she thinks about Timothy MacNeil all the time.
"...I believe that his spirit struggles on. And I do talk to him. And, um, I tell him how sorry I am and I ask for his forgiveness. And I tell him how much I still love him.
"If I could go back in time, I'd do it in ... less than a heartbeat. But I can't," Brae said.