Others chatted in hushed tones to police who manned every entrance to the Strand Shopping Centre in Bootle, hoping that the new, enhanced pictures issued yesterday of the two abductors would jog the memories of shoppers.
The official version of the poster bears the legend: 'Merseyside Police', with the question 'Have you seen these boys?' It has four large colour photographs, one of James in his Teenage Mutant Hero T-shirt, with ice-cream plastered around his mouth. The other pictures show the two boys leading the two-year- old away, with enlarged pictures of their faces.
But in a reflection of the mood of anxiety that has gripped the city, officers have added to some of the posters the plainer directions: 'Cop shop Bootle Strand, opposite Caesars first floor' so that no one is any doubt where to go if they have any relevant information. The police are not proud when there is a child killer on the loose and help from the public is their best chance.
Officers, clutching their blue clipboards, said they had been overwhelmed by the public response. Inside the shopping centre mothers and fathers passed the scores of bouquets and flowers.
In the featureless concrete centre bounded by railway lines and high-rise flats, they clung firmly to the forearms of screaming and reluctant small children, fearful to let go for a moment.
One mother of a boy and girl, aged one and four, who was standing beneath the video camera that captured James's abduction, said: 'I wouldn't dream of leaving them outside a shop for a minute. I was just looking at the flowers and I had to walk away. I was nearly in tears. It affects us all because it's so close, and the poor woman has only got one kid.'
Some of the cards pinned to the flowers bore only simple messages. 'Rest in peace Jamie, from a Mummy and Daddy', or 'Good night and God bless, from a Bootle family'.
Others illustrated the feelings that have crossed the minds of every parent in the country. 'There but for the grace of God, RIP baby James', while another put the poignant question that seems to be on the lips of everyone in the city: 'Why and who?'
Pushing her 14-month-old grand-daughter through the doors of the centre, Veronica Caffrey, 50, echoed the sentiments. 'I was broken-hearted. I couldn't believe that anyone could do that to a little child. They must be evil to do something like that.
'Everybody in the city feels the same about the tragedy. It's more than anger. You would just like to get your hands on them. To be honest, I would bloody hang them. It's not human to do what they did.'
Her feelings of outrage were mirrored in the outbreak of trouble on Tuesday evening, as people took to the streets when a boy was arrested in connection with the murder.
Neighbours surrounded his two-storey red-brick Victorian terraced house in the Kirkdale area of the city, about a mile from Bootle, where James was abducted. In the Strand, people were able to understand the fury which led to the trouble, which stemmed from the feelings of frustration that someone must know who the abductors are.
'If it was my boy, I would know him from those pictures,' said a policeman, ruefully.
Patricia Yunge, 45, said: 'Someone must be covering up for them. Let's just hope, when they're caught, that the family leaves Liverpool. I do not think the family who harboured these children could live in this city any more. The whole thing is sick.'
PC Mandy Waller, who broke the news of James's death to his parents, Ralph, 26, and Denise, 25, said: 'The family are devastated. They are just trying to keep themselves together. Denise is totally shell-shocked.'