Liberty Templeman was beaten unconscious and strangled before being left face-down in a creek to die, a court has been told.
The trial began in the High Court at Whangarei yesterday of a 16-year-old boy charged with murdering and indecently assaulting the schoolgirl in Kerikeri on November 1, 2008.
Justice Raynor Asher continued suppression of the accused's name - he can only be identified as "K" - pending a review at the outcome of the trial, which is expected to last three weeks.
The Crown will call more than 40 witnesses, including a number of youth witnesses who cannot be named.
Crown prosecutor Mike Smith told the jury of six men and six women in his opening address that 24 hours after arriving for a visit to Kerikeri from Auckland's North Shore, Libby was beaten and left to die.
Libby's parents sat in the public gallery for the first day of the trial and were expected to take the witness stand today.
Mr Smith said a post-mortem examination revealed she died from drowning.
She suffered bruising to both sides of her head, nose, eyes, lips, back and buttocks while being dragged.
Mr Smith said that on the day she died, Libby and the accused walked back to Kerikeri from a barbecue.
"He hit her until she fell unconscious, strangled and removed her pants and undergarments up to her knees, dragged her to the creek and left her there face down."
He said Libby was struck a number of times around her head and while bleeding she was dragged, partially naked, to the edge of the creek, before the accused rode his bike home.
The accused then removed his green and white striped shirt, put it inside a plastic bag and hid it in bushes, the prosecution claimed. He handed over to police a blue shirt, claiming he wore it on the day Libby died but CCTV footage of him coming out of a supermarket before her death showed he was wearing a green shirt.
A search warrant was executed at the accused's house on November 5, 2008, and police retrieved the blood-stained, green and white striped shirt.
Mr Smith said during police investigations the 16-year-old - who joined the search for Libby - repeatedly claimed she was fine when they parted ways at Kerikeri High School.
Libby's blood stains were found on his green shirt, shoes and on shoulder straps of his backpack.
Mr Smith said it was a deliberate and intentional act where the accused silenced her permanently because he was concerned Libby may go to police or tell someone else about the assault.
He said on December 7, 2008, the accused finally confessed to killing Libby.
Cellphone records showed text messages from Libby and the accused's phones stopped transmitting from about 6.30pm on November 1.
Defence lawyer Catherine Cull did not make an opening statement after Mr Smith's address to the jury.
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