A child capable of murder

"I squeezed his neck and pushed up his lungs, that's how you kill them."
- Mary Bell to Norma Bell, her co-defendant in the double murder of two young children.
"When Kids Kill" by Jonathon Paul
There are many things which make the horrific aspects of the crimes committed by Mary Bell over the summer of 1968 in the slum area of Newcastle stand out: principally that the killers were children themselves who murdered younger boys.
In what is one of the most notorious crimes of the 20th Century, Mary Bell is just 10 when she starts her murderous activities, strangling four-year-old Martin Brown and three-year-old Brian Howe in separate incidents in Scotswood, Newcastle. Her potential for violence was well known in the local area, although no-one appears to suspect the true depths of her deviant nature.
In May, Martin Brown’s lifeless body is discovered in an abandoned house. Though there is no conclusive proof, it is thought that Mary is alone when she kills Martin. It was one day before her eleventh birthday.

Two months later, on 31 July 1968, Mary, this time along with and her neighbour and accomplice, Norma Bell, Mary would murder again. The victim is three-year-old Brian Howe. After a walk with the pair, Brian is found on wasteland in nearby area that locals call the Tin Lizzy. This time there were disturbing signs and clues to the killers' identities. Mary Bell had carved an crudely shaped "M" into his Brian’s stomach with a razor. Cuttings from his hair are found in the surrounding area.
The two young killers break into a local nursery after Martin’s death and leave macabre messages about the murder. The daubings use childish language and writing, “We did murder martin brown - We murder, watch out. I murder so that I may come back”.
When two young boys befriend and later kill toddler James Bulger in Liverpool, 25 years later, comparisons would be made between these child killers and Mary Bell.