Jozef Puska's brother, Marek, was protecting himself, not Jozef, when he withheld information from gardaí who were investigating the murder of Ashling Murphy, a lawyer has told the Central Criminal Court.
Defence counsel Karl Finnegan SC told a jury that Marek Puska, 36, was entitled to remain silent to avoid incriminating himself.
Mr Finnegan said there was a real risk that the information his client had could implicate him in an offence of assisting his brother after the murder.
Mr Finnegan said the jury might not like the defence put forward but added that it is a legitimate legal defence and they must apply the law.
Mr Finnegan also asked the jury to consider the possibility that Marek did not believe his brother had stabbed Ms Murphy to death when he spoke to gardaí two days after the murder.
Prosecutor Anne Marie Lawlor SC told the jury that Marek knew what his brother had done shortly after 9.30pm on the night of the murder because Jozef Puska told him.
Despite this, Ms Lawlor said Marek and another brother, 38-year-old Lubomir Jnr, failed to disclose vital information when they spoke to gardaí.
Their wives - Jozefina Grundzova, 32, and Viera Gaziova, 40 - burned Jozef Puska's clothes to impede his arrest or prosecution, she said.
Ms Gaziova and Ms Grundzova are charged with impeding the apprehension or prosecution of Jozef Puska by burning his clothes.
Lubomir jnr and Marek are charged with withholding information.
All the accused were living with Jozef Puska, his wife Lucia and 14 children at Lynally Grove in Mucklagh, Co Offaly, when the offences are alleged to have occurred in January 2022.
All accused have pleaded not guilty to all charges.
Jozef Puska murdered Ms Murphy, a 23-year-old schoolteacher, by stabbing her after attacking her while she exercised along the canal towpath outside Tullamore on the afternoon of 12 January 2022.
A jury later convicted Jozef Puska of her murder and he is serving a life sentence.
Delivering her closing speech, Ms Lawlor told the jury of seven men and five women that there is an onus to provide information about serious offences such as murder.
She said Marek and Lubomir Jnr each had information about the murder, including that Jozef Puska had confessed that he "killed a girl".
She asked the jury what possible reasonable excuse either brother could have for failing to tell gardaí what they knew when they gave voluntary statements on 14 January.
Common sense, she said, would indicate that their reason for not telling gardaí was that they did not want their brother to be arrested or prosecuted.
Ms Lawlor said the information they had was vital to gardaí to power the investigation into the murder of a 23-year-old woman who was found "dead in a ditch in inexplicable circumstances".
She said it is "patently obvious" that the information they had was material to the investigation.
When Viera Gaziova and Jozefina Grundzova burned Jozef Puska's clothes, "they knew why they were doing it," Ms Lawlor said and acted without any reasonable excuse.
She added they both admitted to burning Jozef Puska’s clothes and they knew through their husbands that he had admitted to "stabbing or killing a girl".
"As night follows day," Ms Lawlor said the burning of the clothes is linked to their knowledge of what Jozef Puska had done.
She urged the jury to use their common sense and return guilty verdicts.
Mr Finnegan was the only one of the defence counsels to give a speech.
He said that the legislation regarding withholding information was introduced following the Omagh bombing to force people with knowledge of that atrocity to come forward.
However, Mr Finnegan said that the legislation does not remove a person's right to remain silent if they believe that they could incriminate themselves.
Mr Finnegan said that at the time, there was a real risk that his client would be arrested for assisting Jozef Puska after the murder by arranging to get him out of Tullamore or because he knew of the plan to burn his brother’s clothes.
This was a "reasonable excuse" for his failure to disclose information, counsel said, and this is a legitimate defence in law.
Marek's statements were an attempt to distance himself from Jozef Puska, Mr Finnegan said, adding: "He was distancing himself from culpability or knowledge of what Jozef Puska was doing that day."
Mr Finnegan said: "There are elements of this defence that you might not like, but you are here to do a job and I am asking you to apply the law to the evidence."
Closing speeches for the other three accused will begin tomorrow.
