The judge in Robert Black's latest murder trial said while jurors would likely want to throttle the serial killer if he ever went near one of their children they must reach a verdict on evidence not emotion.
Mr Justice Ronald Weatherup said any jury member would naturally try to inflict serious harm on the Scottish paedophile if he ever confronted one of their loved ones.
But as he directed them at Armagh Crown Court, the judge urged the nine women and three men to take a step back and view the case dispassionately.
The convicted triple child killer is accused of abducting and murdering nine-year-old Jennifer Cardy in Northern Ireland 30 years ago, a charge he denies.
Mr Weatherup, who will conclude his directions before sending the jurors out to consider their verdict, also gave them the option of finding Black guilty of manslaughter.
In 1994, Black was convicted of three unsolved child murders in the 1980s - 11-year-old Susan Maxwell, from the Scottish Borders, five-year-old Caroline Hogg, from Edinburgh, and Sarah Harper, 10, from Morley, near Leeds - and a failed abduction bid in Nottingham in 1988.
"All right-thinking people would be appalled about what they have heard about this defendant," Judge Weatherup said as Black looked on from the dock.
"Those of you who have a daughter or niece or other young girl you know would be appalled by what you have heard and would be concerned about what would happen - you of course would not want any children you know to be confronted by the defendant."
Mr Weatherup said the jurors would have been "naturally outraged" when they were told of Black's convictions during the trial.
The schoolgirl was snatched as she cycled to a friend's house in the quiet Co Antrim village of Ballinderry on August 12, 1981. Her body was found six days later in a dam behind a roadside lay-by 15 miles away at Hillsborough, Co Down.