London (CNN) -- Terrorist groups, anarchists and other political extremists are the most obvious potential security threats to the royal wedding on Friday, but the most potent danger comes from obsessive lone operators, say experts.
These 'fixated' individuals are such a threat that in a small office not far from Buckingham Palace in central London a team of psychiatrists, psychologists and police officers are busy trying to counter that threat.
The team is part of the Fixated Threat Assessment Center (FTAC), a unit established in 2006 with the responsibility of identifying and the power to indefinitely detain individuals who harass, stalk or threaten the Royal family and others in public life.
A forensic psychiatrist, Dr. David James, is the clinical director of FTAC and has conducted research into attacks on the Royal household. CNN
