The “Dangerous and Severe Personality Disorder” (DSPD) program of pilot treatment units was established following the high profile double homicide of a mother and one of her two daughters: the very kind of stranger killing that, although in fact extremely rare, the public identifies with most fearfully. This paper describes one of the medium secure DSPD services in terms of the nature of the patients’ difficulties, and the treatment model that was established to address the dual task of reducing the risks they pose to the public and improving psychological health. The impact upon staff and upon teams working with such a disturbed and dangerous group of men is explored. Copyright © 2015 John Wiley & Sons, Ltd.