Omanawa double homicide: One brother confessed to taking part in alleged planned murder before being shot dead

A mother has told a High Court jury that her older son confessed to her about taking part in an alleged planned double-murder before he was shot dead by police.

Samuel Fane, accused of a double homicide in Omanawa in February last year, has been on trial at the Tauranga High Court.

The 26-year-old allegedly fatally shot two men at the Bay of Plenty property with his older brother as part of a plan to help avenge an apparent affair.

"They were both armed and they both knew the plan and to deal with anyone that might get in the way," Crown Prosecutor Anna Pollett said.

The Crown says Samuel agreed to help his older brother Anthony, who was convinced his partner of eight years was having an affair with one of the victims, Paul Lasslett. 

The second man found dead - Nicholas Littlewood - was believed to be in the wrong place at the wrong time. 

"More shots had been fired than those that hit the deceased," Pollett said.

Anthony had already killed his partner, firing crossbow arrows into her head while their two young children were asleep. 

The mother of the pair described the shock of hearing of the alleged murders when her son Anthony visited her.

She said she told him to give himself up, but he said he wanted to go out in a "blaze of glory".

"He was like a lunatic. He was running up and down the stairs thinking someone was on the roof at one stage," she told the court on Tuesday.

"He was paranoid that people were looking in."

Anthony left her home and later died in a shootout with police after he led them on a high-speed pursuit through the streets of Tauranga. Brother Samuel was arrested at a South Island property.

The jury heard it was his "intense loyalty" towards his brother that motivated him to assist in the Omanawa killings, but the defence argues that although he was there, it was his brother Anthony who was ultimately responsible. 

"The Crown perspective there was some grand plan hatched. I invite you to examine the evidence as to this plan. What evidence is there of a plan?" Defence Lawyer Simon Lance said.

Samuel's partner Sarah-Lee Tarei is also on trial, accused of helping him avoid arrest and buying razors so he could shave his head and change his appearance. 

The trial is set down for four weeks.