Scotland’s most senior law officer has hailed as “transformative” a decision by appeal court judges about the way sexual assaults are prosecuted in the country. The lord advocate, Dorothy Bain KC, spoke on Wednesday after seven appeal judges ruled that the distress displayed by a complainer to a witness can be used to corroborate whether a rape took place. Corroboration requires prosecutors to provide another independent source of evidence to prove a crime took place, which can come in the form of forensic or witness evidence. It is one of two unique features of Scots law that campaigners consider to work against the successful prosecution of sexual assault, the other being the use of the not proven verdict, which the Scottish government plans to scrap in a new criminal justice bill. The chief executive of Rape Crisis Scotland, Sandy Brindley, said the change was “seismic”. “Most rape cases never make it to court. In many cases, this is because of the requirement in Scotland for corroboration. Up until now, this has meant that every piece of evidence must be backed up by another piece. This is an issue which particularly affects sexual crime cases. “Survivors of sexual violence often delay reporting what has happened to them, for a variety of reasons. This means that it isn’t always possible to gather forensic evidence to prove that penetration occurred. In England, if a woman is raped or sexually abused but does not report or undergo a forensic medical exam within a short timeframe, it is still possible for her case to get to court. In Scotland, this is far less likely. This isn’t acceptable.” Bain had told the court of criminal appeal in Edinburgh this year that existing practices in the Scottish legal system were “out of step” with other countries and that the nature of sexual assault and how it was committed meant that jurors should be allowed to consider the distress of the victim as being able to corroborate their account of being raped. In a written judgment issued by the court on Wednesday, Lord Carloway, who sat with other six colleagues, upheld Bain’s submissions. He wrote: “It is clear that, in the Commonwealth generally, distress can provide corroboration of a sexual assault, including rape, without any need to corroborate penetration separately. Scots law is out of step with the rest of the Commonwealth. “The answer to the questions in the reference is that a witness testifying to the [recent] distress of a complainer is capable of corroborating direct evidence from a complainer that she has been raped.” Responding to the judgment, Bain said: “Since my appointment, I have sought to do all within my power to deliver justice for women and girls, who are disproportionately impacted by sexual offences. “Today’s decision has the potential to transform the way we prosecute all offences, in particular sexual offences, and will improve access to justice for more victims.”