The man accused of murdering Kiko Li says his "evil idea'' of killing someone only flashed through his mind briefly.
Honglin Yu has denied murdering and stealing the Chinese student's bankcard in May last year.
The 21-year-old was cross-examined at the High Court in Auckland today about text messages he sent to his friend Yongxin Li in the days leading up to the killing in May last year.
One of the messages said "Oh... I even have the thought of killing people... Who do you find disagreeable? I will help you fix him.''
Yu told the court that "it was just an evil idea that flashed through my mind quickly''.
Earlier he told the court that he had been giving Kiko a driving lesson while his friend Yongxin Li was in the back seat.
He said Li began strangling Kiko and he had grabbed Li's arm. At one point Kiko bit Li's arm and screamed before Li brought out a knife and stabbed her.
Yu said he was driving down Scenic Drive at the time, in the early hours of May 19.
"When he pulled the knife out of Kiko, he pointed it at me immediately. I didn't know whether he would stab me as well, he might kill me as well.''
The Crown says Yu and Li had planned to kill Kiko for money.
Yu told the court in Mandarin that he had not wanted the murder to go ahead.
He broke into English to address the jury and said he had made "several silly, silly mistakes.''
He said he should never have text messaged his friend Li about a robbery and kidnapping and should never have mentioned his friend Kiko as a possible target. "It was a stupid, stupid thing to say.''
Yu said he was sorry he had not gone to police and told them what had happened to Kiko but he had been worried that no one would have believed him.
"I was scared. I was being selfish. I didn't want to go to jail for something I didn't do, something I didn't want to do.''
He said had he known Li had a knife that night, he would never have let him into the car with Kiko.
"I thought I knew him. I thought I knew he wouldn't do that but I didn't know. I'm sorry.''
The court has heard of text messages from Yu to Li in the days leading up to the killing. One of them said: "Kiko has probably quite a lot of money in the card. Family is also very rich. May consider it. Furthermore. I know her pin.''
But Yu told the court he never had any intention of hurting Kiko and tried to talk Li out of the planned robbery and killing.
"He decided the target straight away and wanted to kill her,'' Yu said.
He said later text messages showed he did not want to go through with the murder.
Yu said he tried to make excuses to hold Li back from robbing and killing Kiko and sent a text to Li five days before the killing to say "I've obtained two thousand. Put our plan on hold first.''
He told the court that he had been paid the $2000 after referring foreign students to an agent
The trial continues.
