Ambulances being held back from casualty scenes during the Derrick Bird shootings for safety reasons had a significant impact on police operations, a report has found.
Ambulance crews refused to tend to victims until areas were declared safe by police, following health and safety protocol, the inquests into the deaths of Bird and the 12 people he shot dead heard.
An independent review into the response by Cumbria Constabulary to the events of June 2 last year noted that police officers were left at scenes for significant periods of time with seriously injured people.
During later stages, police patrols were diverted from their deployments by taking gunshot victims to the local hospital.
Officers were at the scene of every shooting that North West Ambulance Service was asked to attend, the report said.
In one incident, where surviving taxi driver Terry Kennedy had been shot in Whitehaven, it was only the insistence of a police officer at the scene which prevented a paramedic leaving on the instructions of the ambulance control room.
Assistant Chief Constable of West Mercia Police, Simon Chesterman, who conducted the review, said: "The effect on Cumbria Constabulary was significant. In the event of a future similar incident it is essential that the police service and ambulance service fully understand each other's needs.
"During an incident such as this, it is very unlikely that the police will be in a position to guarantee that the scene is safe. However, it would be reasonable for the public to expect the ambulance service to attend scenes where there is residual risk.
"While Derrick Bird was still at large, the armed police officers had to make containing him their priority. In events such as this, the chances of armed officers being available to protect ambulance staff is unlikely.
"However, where the suspect has left the scene a dynamic risk assessment can be conducted and unarmed staff deployed. In this case, unarmed police officers were at all the scenes."