
An in-depth look at some of the world's most dangerous murderers.

In April 1997, 27-year-old Rachel McGrath is stabbed to death by an unknown attacker in a car park.

Less than 20 minutes after dropping her children off at school, Rachel O'Reilly is murdered.

When Mary Gough is found dead in her family home, her husband Colin Whelan appears shocked.

In March 2005, the Gardaí recovered human body parts from the Royal Canal in Dublin.