The man accused of raping and murdering Blessie Gotingco has told a jury the police planted his DNA on swabs used to take samples from the body of the mother of three.
The 28-year-old man, who has name suppression, is giving evidence in his own defence in the High Court in Auckland.
He said he crashed into Mrs Gotingco in his car by accident and put her in his back seat to take her home because he did not want to breach his curfew.
He said he thought she was dead after he ran over her but never checked for a pulse.
The accused admitted stabbing Mrs Gotingco to make it look like a random attack, rather than a car accident, because he did not want the police to come knocking and notice his damaged car.
The accused also said GPS evidence that put him at the scene of the crash and at the cemetery could also have been manipulated.
He said he was out at night trying to buy drugs when the crash happened.
The man said there was no response from Mrs Gotingco and he drove her to his home, where he stabbed her in his garage.
"She wasn't moving or making any noises I just wanted to get out of there to be honest, you know it was sort of my first reaction was to just get in my car and drive off.
"But I knew because of the GPS that if somebody found her they would know that I was there as well."
He denied raping her and said he was sorry for what he had done.
The man said he was high on methamphetamine at the time and something took over him.
Earlier he told the court he turned to drugs after a series of family tragedies.
In front of a packed public gallery, the man spoke of how his aunt died, his mother had a stroke and his partner had a miscarriage after three months.
The man said he had no one to talk to and turned to drugs, starting with synthetic cannabis, moving to cannabis and then methamphetamine.
He said he would smoke drugs in the Eskdale cemetery - the site where police found the body of Mrs Gotingco two days after she went missing.