The abduction and murder of schoolgirl Jennifer Cardy does not bear the signature of serial killer Robert Black's other murders, his lawyer has said.
Defence barrister David Spens QC also said the prosecution has failed to prove that Black was even in Northern Ireland on August 12, 1981 - the day that the nine-year-old disappeared.
In his closing statement at Armagh Crown Court yesterday, Mr Spens said the case was full of unpleasant and harrowing detail, but warned the jury to set aside sympathy for the Cardy family.
"Some (detail) is obscene, repulsive and desperately sad and must be very difficult for Jennifer Cardy's parents to hear this," said Mr Spens.
"You will no doubt have sympathy for the family. At the same time you will have absolutely no sympathy for Mr Black."
He added: "It may be some, or all of you, will want to convict him and give a sense of closure to the Cardy family. But you do not decide your verdicts on a wave of sympathy. You have to weigh the evidence dispassionately."
Jennifer was abducted close to her Ballinderry home 30 years ago as she cycled to a friend's house. Her body was discovered floating in water at a dam close to Hillsborough six days later.
The prosecution has told the jury that Jennifer's murder bears strong similarities to the murders of three young girls who were killed by Black in the 1980s as he travelled across the UK and Ireland as a poster delivery driver.
However, Mr Spens told the court that there are "striking differences" between Jennifer's killing and those murders.
He said there was no evidence that Jennifer had been sexually assaulted, unlike in some of the other cases. Mr Spens added that the young girl had been wearing trousers when she was abducted and told the jury Black preferred the "schoolgirl" look, with the children wearing shorts or skirts.
"Whoever abducted and murdered Jennifer Cardy behaved in a very different way to that which Mr Black's convictions demonstrated he behaved. These striking differences, we would submit, suggest it as not Mr Black who was responsible," said Mr Spens.
Throughout the trial prosecution evidence was presented to the jury in a bid to show Black had been in the area at the time of Jennifer's murder and therefore had the opportunity to abduct her. They said a paper trail of petrol receipts and work records placed Black in the vicinity.
But Mr Spens told the jury yesterday that the prosecution had failed to prove Black was in Northern Ireland on August 12, 1981.
There is also no forensic evidence linking Black to the abduction and murder, Mr Spens said.
Addressing the jury for more than four hours, Mr Spens concluded by telling them that no matter how unsettling the case against Black, particularly the details of a recurring fantasy he had of abducting and sexually assaulting young girls, it does not tell them that he had been in Northern Ireland on the day Jennifer was murdered.
He said that when they examine the case they should be led to the conclusion "that the perpetrator is somebody other than Mr Black".
Serial child killer Robert Black is on trial for the murder of nine-year-old school-girl Jennifer Cardy who was abducted and killed 30 years ago. Summing up his case for the jury, a defence barrister said yesterday there was no reliable evidence to place Black in Northern Ireland on the day Jennifer was murdered.