SCOTLAND’S top law officer, Lord Advocate Frank Mulholland QC, will step down from the role after the Scottish Parliament elections in May after five years in the job.

Mulholland said in a statement that it had been a “real privilege” to lead the prosecution service in Scotland at a time when the Crown’s expertise in dealing with domestic abuse and serious organised crime had seen it become “one of the most effective in the world”.

“It has been a real privilege to serve as Lord Advocate, leading Scotland’s prosecution service and providing independent legal advice to the Scottish Government,” he said.

“However, after nine years as a law officer – the last five as Lord Advocate – I have decided it is the right time to step down and do other things. In recent years the Crown has embedded specialisms in the way it does its job.

“Our expertise in handling offences including rape, domestic abuse, serious organised crime, counter-terrorism and cold cases has helped us become one of the most effective prosecution services in the world and given victims greater confidence to report crimes.”

Mulholland previously served as Solicitor General and succeeded Dame Elish Angiolini QC as Lord Advocate in 2011. He will formally step down when his successor is appointed by the Queen.

First Minister Nicola Sturgeon said Mulholland had fulfilled his “challenging” roles with dedication, energy, integrity and intellect, adding: “He has played a central role in many innovations to our justice system, including leading Scotland’s first successful ‘double jeopardy’ murder prosecution and agreeing a historic communiqué with the heads of prosecution services from across the UK and Ireland to work together to tackle the cross-border crime of human trafficking.

“He has introduced a number of significant reforms to the Crown Office including the establishment of the National Sexual Crimes Unit and the appointment of Scotland’s first specialist prosecutor to deal with domestic abuse – two reforms which have strengthened the rights and confidence of victims of these horrendous crimes.

“It is clear that he has worked to bring about change to ensure that the system makes a real difference to people’s lives, and his dedication to the law and his compassion for others has been behind that drive.”

There has been some criticism of the Lord Advocate during his tenure, most recently over the Crown’s decision not charge Harry Clarke over the Glasgow bin lorry crash in 2014 and allegations relating to its position on an independent inquiry into the Lockerbie bombing.

Pressure group Justice for Megrahi (JfM) believe Abdelbaset al-Megrahi, the only man convicted of the bombing, was innocent.

Iain McKie, from JfM, said Mulholland’s position had been untenable since 2012, when he and the Crown Office dismissed serious criminal allegations the group made in connection with the investigation and trial – before police had investigated them.

“This bias and prejudice was recently criticised by leading Scottish legal and political commentators including Brian McConnachie QC, Professor Alan Page of Dundee University and MSPs Patrick Harvie and John Finnie,” said McKie.

“While the Lord Advocate’s resignation is to be welcomed, he is yet to be held to account for this appalling episode.”

Solicitor Aamer Anwar said he would be sorry to see Mulholland go.

He added: “The Crown Office that victims and their families deal with today is very different from the ‘gentleman’s club’ I experienced over 16 years ago in the Chhokar case. That change is in a large part due to Frank.”