A teenager stabbed and strangled a County Tyrone pensioner to get money to pay his rent, a court has been told.
The 17-year-old, who can not be named or identified for legal reasons denies killing Francis O'Neill.
The 78-year-old was found dead at his Omagh home in 2009.
A prosecution lawyer at Dungannon Crown Court described the retired psychiatric nurse's murder as "brutal".
Prosecuting QC Liam McCollum told the jury of seven men and four women that the teenager claimed in a "fantastical tale" that he had found the pensioner dead in his Brook Valley home in Omagh on 11 April 2009.
The lawyer further claimed that in police interviews the youth finally admitted taking the pensioner's wallet, later found in his flat, and using £80 he took from it to pay his rent.
The jury and trial judge Mr Justice McLaughlin also heard that initially the teen, who later returned and ransacked the pensioner's home, claimed that he'd borrowed the rent money from his father.
Mr McCollum said when paramedics arrived they found Mr O'Neill sitting upright in chair in his living room and that while there were no visible signs of injury, there was a small amount of blood on his jumper.
A post mortem examination later revealed that death was due to strangulation, either by hand, or by holding Mr O'Neill in an arm-lock. He had also been stabbed in the right side of the neck, but this played no part in his death.
The prosecution lawyer told the jury that they would come to the "inevitable conclusion" that the youth had gone to "Mr O'Neill's house and murdered him".
However, the lawyer admitted that the prosecution did not have any "direct evidence" linking the teenager to the murder, and that their case was based on circumstantial evidence.
Mr McCollum said there were three very important parts to the evidence, "the general circumstances of his behaviour and demeanour throughout the day", the forensic evidence, although this is partially neutral, and thirdly, what he told police".
He claimed later that "the accused had the opportunity and motive" for the killing and that either Mr O'Neill had opened the door to him, or he had climbed in a back window on which only his fingerprint was found.
According to Mr McCollum, the youth's "behaviour after allegedly finding Mr O'Neill dead was very peculiar" in that he failed to initially tell anyone, or even make an annoymous call to the emergency services, but spent the rest of the evening "drinking and carrying on".
He took Mr O'Neill's wallet and a short-time later paid his friend the rent money he owed him, before later returning to Mr O'Neill's home where he "ran amok ... went beserk" and ransaked the place.
"What he would have you believe," Mr McCollum told the jury, "is that he stumbled upon the deceased".
"This is simply not a plausible story ... it defies common sense," said the lawyer who went on to add that this was a "fantastical tale .... which does not stand up to any logic."
The trial continues.