David La Rooy, who is on a three-year posting at the university, funded by the Scottish Institute for Policing Research, says Scottish child abuse victims are less likely to get justice than those in England and some other countries.

Latest figures show that 76% of those going to court on child abuse charges are convicted – but La Rooy says most of the cases which reach court involve adults abused as children, children whose testimony can be backed up by strong forensic evidence, or cases such as one which recently saw eight paedophiles convicted in Edinburgh, when the internet provided reams of damning email and photographic evidence.

In fact, Herald Society has established that the number of people convicted of sexual offences against children in Scotland dropped by almost one-quarter last year to 247, the lowest level for a decade.

There are no figures available for how many complaints were made to the police which never reached court.

But La Rooy says there are reasons to suspect the percentage of all child abusers who are convicted by the Scottish courts is very low. Flawed interviewing of child abuse victims is a major problem, he says, with Scottish methods of interviewing lagging behind those of other countries.

Another factor is that Scotland’s legal system calls for a second piece of evidence, apart from the child’s.

La Rooy is to publish research on the interview process next month and is calling for a push to improve standards, keeping them in line with the latest research.

He argues that, given the rigours of Scots law, it is particularly vital that initial interviews with the victims should be of the highest standard.

“By its very nature, child sexual abuse is a secret crime,” he says. “It is often in their own home. And there often isn’t much evidence of it.

“It is imperative that the first interviews with the victim are of the highest possible quality. We know from research that high-quality interviews can help the police to find that extra piece of evidence to prove that the child is telling the truth.”

Since the Orkney child abuse case of 1991, Scotland, as in other countries in the developed world, has guidelines insisting that adults interviewing children should ask open questions such as “tell me what happened”, and avoid painting pictures of what they think might have gone on.

According to La Rooy, the complication is that, in countries where such interviewing is carefully monitored, evidence is mounting that, even when trained, most people don’t stick to the guidelines.

“Findings from England and Wales found that the average interview was of low quality,” says La Rooy. “That research echoes findings in countries such as the US, Israel, Norway and Sweden. In Scotland there is no forensic interview research being conducted. But it is likely that the picture here is similar.

“It is hard to know why the professionals involved don’t follow the guidelines. Most of them have had some training and, if you ask them what they should be doing, they know. Why they don’t is the million-dollar question.”

La Rooy argues that the spotlight should be turned on the professionals involved, and they should be given constant support, evaluation and training.

“To do a good interview requires a really good understanding of how memory works,” he says.

New requirements for videoing initial interviews with Scottish child sex abuse victims will increase the importance of getting things right, he adds.

“If they are not done properly, it makes the job of the defence so much easier. If the defence can find suggestive questions being asked, the evidence won’t stand up.”

La Rooy pointed to a new protocol which was first drawn up in Israel. A seven-step interview template for use in these situations, it lays out the exact questions which should be asked, just leaving blank spaces for names. A trial in England showed it was effective at improving the quality of initial interviews.

La Rooy, who is originally from New Zealand and subsequently spent time in the US working with Michael E Lamb, one of the foremost international authorities on this subject, is keen to start a project in Scotland to evaluate the interview process here and perhaps bring in the protocol. “I am keen to bring some of this expertise into the Scottish system,” he says.

During his first year in Scotland, he researched repeated interviewing and the effect it has on children’s memory. He interviewed children soon after they had seen a pirate show. Interviewing them once again the next day produced much more detail of what happened. “The detail we got the next day was more than 90% accurate. Sometimes repeated interviewing can be useful but it has to be done in the right way.”

Many of us will recognise the experience of remembering something after a conversation that we forgot to say at the time, he adds. “The trouble is that, in court, defence lawyers call that inconsistent. They ask why they didn’t come up with these details at the first interview? There is very little understanding of how memory works.”

Andrew McIntyre, head of victim policy at the Crown Prosecution Service, says the establishment of a new sexual offences investigation unit should bring an improvement in the service. “There is a clear policy in favour of bringing abusers to justice but we also want child victims and witnesses to be treated as children within the court system.”