On December 2 2015, a jury at the High Court in Napier were tasked with one of the most serious, and also one of the most perplexing decisions I've come across as a journalist: The jurors had to decide whether a young woman, Lyree Sayers, tried to commit suicide by deliberately crashing her car into another vehicle.  The crash killed the other driver, Pam McGarva.  The jury had to weigh up whether Lyree Sayers was guilty of manslaughter, or whether the fatal car crash was some sort of unexplainable accident.

Pam McGarva was on her way to her weekly quiz evening at the Napier RSA.  She was driving along Prebensen Drive when her car was hit head-on in mid-July 2014. She died in hospital almost a fortnight later.  She was aged 55, a well known teacher at Carlyle Kindergarten.  She was described as full of fun, bubbly, bright and talented, a lovely person, very warm who made everyone feel special.  The kindergarten held a candlelight vigil for her as she lay in a coma in Hawke's Bay Hospital.  Her hospital room was filled with messages and pictures from children.

Lyree Sayers - the woman in the dock - was 24-years-old at the time of the crash.  She had a former career in the Navy.  She was living with her partner in Tamatea and was in regular contact with her family.  Her father, Patrick, described her in court as a happy lass whom he would often visit.  She suffered depression and was taking medication for it daily.  Her friends and family knew of her mental illness and knew she was being treated. 

She told friends she had attempted suicide in the past.  She made a threat to her friend that if her boyfriend ever left, she would kill herself. 

Lyree Sayers was distraught when she got into her car that night.  Her partner said it was like she was broken.  He had just moments earlier ended their relationship.  They had a heated argument - she was crying and angry and lashed out by kicking and scratching him.  He told her to leave, so she got into her car and sped away.  She was driving along Prebensen Drive, near Taradale, just after 6pm on a Wednesday night when her car veered into the other lane and hit the only other car on the road.  Lyree's car tumbled 70 metres down the road.  She suffered head injuries and a broken ankle. 

Pam McGarva was worse off.  She was left in a coma with serious head injuries and died 11 days later.

The fatal crash happened in the middle of winter, on a dark night in July.  It had been raining that day so the road was wet, but it had stopped by the time Lyree Sayers and Pam McGarva got into their cars.  It was a stretch of road in a semi-rural area that had no lighting.  It was in a 100 kilometre-an-hour speed zone, and was wide, straight, and flat.  The lanes had a two and a half metre median strip between them.  There was no other traffic on the road.  There were no eye witnesses.

On the night of 9th of July, 2014, Lyree Sayers' car was mechanically sound.  It had a current warrant of fitness, her tyres did not blow out, she was not impaired by drugs nor was she over the legal limit for drink driving, she was not texting or making a phone call on her cell phone, she did not fall asleep at the wheel.

Motorists who came across the crash scene were adamant that Lyree Sayers was wearing her seatbelt when they were comforting her in the wreck of her Nissan.  One couple even said that she was damn lucky she was wearing her seatbelt otherwise she would have ended up through the windscreen.  

Yet the Serious Crash Investigator found no signs the belt was being worn at the time of impact.  His opinion was that it was highly unusual for the seatbelt to have no signs of damage if she had been wearing it - a coincidence he had never seen before.

Lyree Sayers, as is her right, never made a statement to police.  She went to the Napier Police Station twice, accompanied by her lawyer, but never said a word.  She also elected not to take the stand at her trial. 

During the three day trial, her lawyer raised alternative theories for the jury to consider.  He wanted them to think about all the other possible reasons her car could have made a gentle arch-like movement from her lane into the other, and smashed into Pam McGarva's car. 

Eric Forster asked the jury to think about whether an animal could have run onto the road at that exact same time. Forster said his client might have been distracted by looking for her cellphone, which she might not have known she had actually left at home.  He queried why Lyree Sayers would wear her seatbelt, if she wanted to commit suicide.  There were three witnesses claiming they saw the belt on her.  His theory was that Lyree was heading to her parent's house in Puketapu that night, which was often her refuge following an argument with her boyfriend.  Why would she try kill herself when she was heading to her family for solace and comfort?  She wasn't driving the most direct or usual route to their house - but nonetheless, that's where she was most likely heading. 

While investigators couldn't find an accidental cause of the crash - Eric Forster says that doesn't mean there wasn't one. Anything could have happened. 

The prosecution put it to the jury that if it was an accident - what a terrible coincidence it was, that it caused her to collide with the only other vehicle on that stretch of road at that exact time.  Clayton Walker summed up by saying it's a two-fold tragedy - where an innocent life has been lost and a terrible thing that it was because of the determination that another life was not worth living.

In the end, the jury did not accept the theory that Lyree Sayers was trying to commit suicide by deliberately turning her car into the path of another.  They found her not guilty of the manslaughter of Pam McGarva. 

The McGarva family have been left devastated.  In their words - they've been cheated.  They wanted someone to be held accountable.  They didn't get that, nor have they got an explanation of what caused the crash.

As Neil McGarva put to me - Pam McGarva's death will now be put down as an 'unexplained accident' and they will always be left wondering.

Annette is Newstalk ZB's reporter in Napier where she covered the trial.