Criminal prosecutions are falling in Lancashire, according to Ministry of Justice figures.
This drop in cases is happening in most areas of England and Wales. Legal experts say that police don't have enough resources to complete investigations to the standard required by the Crown Prosecution Service, leading to cases being shelved.
The latest MoJ data shows that 530 cases reached crown courts in Lancashire, between April and June, down from 798 over the same period in 2014.
Crown courts deal with the most serious crimes, such as murder, robbery and sexual offences. Magistrates’ courts can only hand out a maximum sentence of six months’ imprisonment, so crimes which require longer jail terms go to trial at crown court.
The most common type of offence dealt with in the Lancashire Local Criminal Justice Board area was physical violence against a person, accounting for 23 per cent of all crown court appearances.
The CPS carried out 37 prosecutions for robbery over the time period, seven per cent of the total cases.
Ian Kelcey, a solicitor at the Law Society, said: "The CPS are now demanding that the cases have to be trial-ready before they will authorise going to trial.
"The problem is that police forces do not have the manpower to put together the information the CPS wants and I suspect a lot of cases have just not been pursued because it is too much trouble from them."
"I used to do quite a lot of shoplifting cases but now you get three or four a year because they don’t bother prosecuting people unless they are persistent offenders. I am afraid this is what underlies these figures."
Assistant Commissioner Martin Hewitt, of the National Police Chiefs' Council, said: "One factor that may have impacted on referrals is the increase in the amount of digital material on a variety of devices that needs to be analysed.
"This includes obtaining material held by third parties and the subsequent disclosure of what is considered relevant material. This can take many months and in some cases impact on the participation of complainants."
Rick Muir, the director of the Police Foundation, a think tank, said that budget cuts are behind the fall in case numbers.
He said: "If you have 20,000 fewer police officers today than in 2010-11, then fewer crimes will be solved and fewer will end up in court. Recorded crime has been increasing in recent years, so if the number of offences being tried in court is lower that tells us that the police are clearing up fewer."
In England and Wales, only two out of the 48 Local Criminal Justice Boards dealt with more cases than four years ago.
In Lancashire, sexual offence cases were prosecuted 51 times, 20 fewer than four years earlier.
Although the number of sexual crimes reported to police has almost doubled since 2014 across England and Wales, sexual offence cases in court dropped by 52 per cent.
Mr Muir added: "Sexual crime takes longer to investigate than average because of its complexity, but this trend is also down to having fewer police officers."
A Home Office spokesman said: “Changes in charge rates are likely to be driven by improved crime recording by the police, and forces taking on more complex crimes which take longer to receive an outcome, such as domestic abuse or sexual offences.
“Police have the resources they need to carry out their vital work and we have provided a strong and comprehensive settlement that is increasing total investment in the police system by over £460m in 2018-19."