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

Robert Howard manipulated and preyed on vulnerable women across countries.

Teen Mhairi Julyan was murdered, and forensics led police to violent repeat offender Gavin McGuire.

Gardener William Howell used his van as a "murder mobile," killing women and dumping bodies.

Police in Aurora, Colorado find the body of a young man in his own home with a bullet wound to the head.