The Psychology of Terrorism 2nd Edition. Routledge, 2014.

The Psychology of Terrorism 2nd Edition. Routledge, 2014.

Divided We Stand: The Strategy and Psychology of Ireland's Dissident Terrorists. Oxford University Press, 2013.

Divided We Stand: The Strategy and Psychology of Ireland's Dissident Terrorists. Oxford University Press, 2013.

Terrorism Studies: A Reader. Routledge, 2011

Terrorism Studies: A Reader. Routledge, 2011

Walking Away from Terrorism, Routledge, 2009

Walking Away from Terrorism, Routledge, 2009

Leaving Terrorism Behind: Individual and Collective Disengagement. Routledge, 2009

Leaving Terrorism Behind: Individual and Collective Disengagement. Routledge, 2009

The Psychology of Terrorism. Routledge, 2005

The Psychology of Terrorism. Routledge, 2005