A man accused of killing a woman and her daughter says the real murderer was a man called James and it was only a "stunning lapse of judgement" that saw him become involved.
Pakeeza Yusuf was found buried under Takapuna overbridge with her three-year-old daughter Juwairiyah "Jojo" Kalim in October 2014.
The Crown alleges the pair were murdered by Kamal Gyanendra Reddy, 42, at the end of 2006 or start of 2007.
The defendant unwittingly made confessions to undercover officers and led them to the burial site after an extensive six-month police operation.
In a secretly-recorded interview he told police he had strangled the adult victim with an electrical iron cord before smothering the girl with a pillow.
His lawyer Jonathan Krebs said Reddy felt compelled to get into the witness box after the "powerful" prosecution evidence.
"Mr Reddy has no option but to explain to you why he would make these confessional statements if in fact he's not guilty," Mr Krebs told the jury.
"He'll have to address the question that has no doubt burned in your minds: If Mr Reddy is not guilty, if he falsely confessed, how is it that he could take undercover officers to the location of the deceased? How could he show them where the graves were and why would he do that?"
The lawyer said his client's link to Ms Yusuf came about when her father "offered her up" to help Reddy with his visa issues.
In 2006, she was seeing a man called James and living in Howick, he said, when the defendant bumped into the couple and was given their address.
Mr Krebs told the jury Reddy visited one day but was told by James that Ms Yusuf and Jojo were out.
However, the following night, the man came to the defendant's south Auckland property and told him he had killed the pair.
"In a stunning lapse of judgement, he agreed to help," Mr Krebs said.
The defence case is that Reddy "in another lapse of judgement" sought advice from his uncle Bal Naidu about where the bodies could be buried.
He only said he was the killer because he thought it more likely Mr Naidu would help in that case, Mr Krebs said.
Earlier in the trial, Mr Naidu gave evidence of seeing something under a blanket in the back of Reddy's car.
Mr Krebs said that was just the defendant's tools, which were kept under cover for "security reasons".
When Reddy's uncle took him to the spot under the Takapuna bridge - an area he had been working for Fletcher Construction - he relayed the information to James.
That was how he knew where the bodies were buried, Mr Krebs said.
"He didn't kill Pakeeza and Jojo. James killed Pakeeza and Jojo," he said.
"Mr Reddy assisted with advice as to where the bodies could be disposed of. He's guilty of being an accessory after the fact but he's not guilty of the murders."
In the witness box this afternoon, Reddy described James as a part-Indian man - clean shaven, well built, taller than him and neatly dressed.
He did not know his surname, he told the court.
The trial continues.