Sarah Waters* was terrified but she was assured by the police that she had done the right thing. As they took her husband away in handcuffs late at night they explained that even if the courts granted him bail the next day, there would be special conditions attached and he would not be allowed home.

The next morning she returned from the shops with her children to discover that he had already returned to their house in Aberdeen. She telephoned the Crown Office to be told that his case had been "diverted" and that he would not be going to court. The charges of breach of the peace and assault had effectively been dropped and he had been released from custody.

"I couldn't believe it," she says. "I had explained to the police that this had happened within a context and history of domestic abuse and they reassured me that it would be dealt with appropriately. I wasn't even told that he had been released.

"Imagine how angry someone would be after being locked up in cells all night. And they let him go straight home. If the circumstances had been different, if it had been someone with a drink problem, this could have turned into a murder case.

"I phoned the fiscal's office to complain but they stood by the decision. They said certain cases were selected for diversion and that this was one of them.

"There was no assessment done of his mental state nor of where he planned to go after being released from the cells. It seems incredible that he was allowed to go straight home to where I was with the children. He wasn't even seen by a social worker."

Thousands of cases have been "diverted" from the courts since March when the Crown Office introduced a new initiative aimed at removing "low-level" cases from Scotland's overburdened courts.

The aim was to address minor cases such as shoplifting, and low-level breaches of the peace, at the fiscal level rather than them clogging up the courts. Offenders would be sent letters notifying them of the fact they had been diverted with calls for them to pay fines of up to £300 or compensation of up to £5000.

They would be given 28 days in which to reject the penalties. Those who did not respond were deemed to have accepted.

Streamlining and speeding up the system to allow the courts to concentrate on the most serious cases made perfect sense. Court cases may now be processed more quickly but at what cost?

Summary criminal cases account for 96% of criminal court business in Scotland and in 2004 the McInnes report found huge delays in the system.

In 2003, 24% of cases in the sheriff court and 16% in the district court had not been disposed of 50 weeks after the offence had been committed. McInnes recommended more use of fines and other diversions to free up court time.

Direct action by the fiscal is not a new concept. Last year the Crown Office offered some 52,000 fiscal fines of £100 or less but a significant proportion went unpaid. There were 13,985 fines paid between 2002 and 2003.

However, the scale of the penalties and process of offering them has changed considerably.

Under the old system those asked to pay a fine had to "opt in" rather than opting out. Failure to reply was seen as rejection of the offer in favour of going to court and less than half were accepted.

Under the new system which started on March 10, failure to respond is seen as tacit acceptance of the offer. Trials indicated that a far higher proportion - more than 75% - would pay the fines under the new opt-out scheme.

Overall the Crown Office predicted in April that an additional 28,000 would be diverted from court under the measures.

In practice the levels of diversion and types of cases affected seem out of line with predictions.

"Crime seems to have disappeared overnight in Airdrie," said one sheriff court official. "We are seeing really serious cases being sent for summary complaint including assault to severe injury.

"This is ridiculous. Clearly the fiscals can now get through the cases quicker and don't have to find extra people to take the cases in court. Cited cases seem to be down by 80% not 20%."

The Crown anticipated that approximately 15% of cases would be diverted under the new scheme. However, anecdotal reports from courts such as Airdrie and Glasgow suggest that more than half are being diverted - a fact the Crown disputes.

"I can't see how this is about protecting the public from harm," says Gerry Considine, a lawyer with the Glasgow Bar Association. "This is undermining the credibility of the justice system. For those sent the letters there is a presumption of guilt and for the victims there is nothing."

But the Crown says it is not true to say there has been a 50% drop in prosecutions, saying the number of reports from the police has reduced by 10% as a result of the introduction of police fixed penalties.

They also say the number of cases prosecuted in sheriff courts dropped 9% between February 2008 and March 2008 and 12% between February 2008 and April 2008, while the proportion of all cases prosecuted in district courts has increased from 24% of all prosecutions in February 2008 to 26% in March 2008.

The Crown admits, however, that it is possible that serious cases which should not been diverted have been, which "is why the impact of the reforms is being closely monitored and reviewed by area procurators-fiscal".

Examples of diverted cases cited by victims and lawyers include an offender who was fined and asked to pay £100 compensation to a young woman he glassed in the face, plus fines for serious assault and incidents of domestic abuse.

In addition to the thousands of cases expected to be diverted over the next year, there will also be a significant proportion downgraded from sheriff to district court and solemn to summary. Recent examples include sex offences against children.

"We have some of the cases sent to summary complaint remitted to the high court - that's how serious they are and how inappropriate it is," says John of the Edinburgh Bar Association.

"People who in the past would have probably received a prison sentence, are being diverted from court altogether. We have gone from zero tolerance to people not being taken to court at all."

Lawyers, some would argue, have a vested interest in that they are losing out on significant amounts of business, but these concerns are also being raised by victims, sheriffs and clerks.

Despite all the high- profile campaigns and policy assurances on how seriously domestic abuse will be taken by the authorities, Mrs Waters was left to deal with the problem on her own.

"It really made me think that if I was in the same position again it would not be worth contacting the authorities," she explains. "If they were not going to take it seriously I would not have gone through the trauma of reporting it.

"My husband has now got help and I think it would be counter-productive to start again and drag him through court, but I'm concerned about what will happen to other women who seek help. People need to be told what is happening in practice."