The shooting of a man in Brighton and Hove is a chilling reminder of the extent the police will go to protect our safety.

The decision to pull the trigger may have to be made in an instant, under pressure and is the most difficult task any police officer can be asked to undertake.

Yesterday's incident brings the number of shootings in Sussex to four in 20 years.

In the most controversial case, unarmed James Ashley was killed when police raided his home in January 1998.

The thin line between the lawful and unlawful killing of a suspect has prompted the Association of Chief Police Officers (Acpo) to review the way officers use firearms. Five police forces are even trialling the use of stun guns to cut back on the number of people killed.

Acpo guidelines state guns should only be used after conventional methods of negotiation have failed.

Police have a duty to protect the public but they also have a responsibility to set the standards the public is expected to follow.

The fact Sussex Police has asked the Police Complaints Authority to examine the latest incident, overseen by an officer from Kent Police, shows how mindful the force has to be in scrutinising its own actions.