A controversial scheme which uses civilians to investigate crime is to be rolled out across at least one police force area – and will be expanded to help solve murders and serious sex offences.

A Scottish Government-funded pilot was so successful in Falkirk that Kevin Smith, chief constable of Central Scotland Police, said it was now being adopted as a force-wide policy.

He added that he would also consider making greater use of civilians in surveillance and public protection.

The Priority Crime Unit uses trained investigative assistants, who are paid about £22,000 a year – the same as a constable – to look at less serious, high-volume crimes, such as housebreaking and vandalism, freeing up police officers to carry out patrols and undertake more serious investigations.

It has covered more than 4,000 cases but the investigators have also been used in several high profile cases including serious assaults, sexual crime, robbery and murder.

The pilot area in Falkirk has seen a 14% reduction in reported crime. The evaluation of the scheme – which has just been completed after running for two years – found that of 1,000 victims, only two were unhappy with the way their incident had been handled.

When dealing with more serious crimes the unit provided a support function, conducting door-to-door inquiries and scanning CCTV.

“This is not policing on the cheap,” said Mr Smith. “It is actually quite expensive but I am convinced of its merits. It is about how well we look after victims.

“It has given us greater capacity for freeing up officers from bureaucracy. Victims of crime said that where the PCU dealt with their concerns they felt a lot better so we are now in the process of rolling it out.”

The Government provided £500,000 of funding for the pilot. From April onwards the force will pay the full costs of the unit – expected to be about £1 million for the force area.