Vicious murders can often be motivated by a sexual element. Some of the grislier details of the murder of Jamie Bulger may indicate this here to a lesser degree, but while that was a working theory of Merseyside Police for a time, it’s not widely believed to be a motivator now.
Jon Venables' psychiatrist, Dr. Susan Bailey, later reported that 'on visiting and revisiting the issue with Jon as a child, and now as an adolescent, he gives no account of any sexual element to the offence.'