There was an air of inevitability about the arrest today of Nicola Sturgeon. The SNP had been braced for it. But that doesn’t make the sight of the former first minister of Scotland being taken into police custody any less extraordinary and, to many SNP observers, any more justified.

Hadn’t her successor in Bute House, Humza Yousaf, said only recently that: ‘We are past the time of judging a woman on what happens to her husband’. Well, no one seems to have told Police Scotland. Ms Sturgeon’s arrest follows the taking into custody two months ago of her husband, the party’s chief executive, Peter Murrell. After being questioned by detectives, Sturgeon was released this evening without charge, in what the police describe as a continuing investigation.

In April, following the arrest of the National Treasurer, Colin Beattie, a number of SNP insiders had forecast that ‘Nicola will be next’. She is the only senior SNP official named on the party’s most recent financial accounts who had not been arrested under Operation Branchform into the finances of the Scottish National Party. The 2021/22 party accounts identify her as one of three ‘registered officers’ alongside Mr Murrell and Mr Beattie.

Sturgeon has always said she would ‘fully cooperate’ with the two-year long police investigation into what happened to the £600,000 in donations raised after 2017 for an independence referendum campaign that never happened. That campaign fund was supposedly ‘ring fenced’. In 2019 it emerged that most of it had disappeared into the general expenditure of the SNP. A number of SNP supporters on social media complained that this was not an acceptable use of the funds.

In 2021, after a series of complaints from individuals in and out of the SNP, Police Scotland decided to investigate. The first formal complaint was made by the outspoken former member of the radical ‘Scottish Resistance’, Sean Clerkin. Perhaps his reputation as a rabble rouser is why the SNP initially failed to take the matter seriously. The party’s argument all along has been that the Scottish National Party is an ongoing campaign for an independence referendum, as its election manifestos clearly state. How therefore could these funds have been in any way misused? Police Scotland evidently thought differently and that there was a case to answer.

On April 5th, officers mounted a spectacular raid on Nicola Sturgeon’s Uddingston home which she shares with her husband, Mr Murrell. A forensics tent was erected in the front garden and no fewer than ten officers and six police cars were stationed in the road outside. Ms Sturgeon apologised to the neighbours for the disturbance and tried to put a brave face on what was a presentational catastrophe.

The ‘optics’ were appalling and highly damaging to the party image, as Scotland’s leading psephologist, Professor John Curtice, told BBC Scotland’s Good Morning Scotland programme the next day. The Edinburgh headquarters of the Scottish National Party was also raided in the full view of the TV cameras and boxes of evidence removed for examination. Later, a £100,000 motorhome, apparently purchased by the SNP, was seized by police from the driveway of Peter Murrell’s mother’s home.

During the April raid, Peter Murrell was arrested and taken into police custody ‘as a suspect’ in the investigation. The fact that he was later released without charge was scarce compensation for an ordeal which many in the SNP believed at the time was unnecessary. There was widespread disquiet in the party about the high-profile arrest. Nicola Sturgeon’s former senior special adviser, Noel Dolan, who is no longer regarded as an ally of hers, said he was ‘appalled at the heavy-handed behaviour of Police Scotland’ in staging ‘a theatrical display like something out of a crime thriller’. After the arrest of Colin Beattie in April, which upstaged Humza Yousaf’s first major speech to Holyrood about his plans for government, one senior SNP figures were reported in the Times as saying that the timing of the police action ‘stinks’.

Further comment on the circumstances of Nicola Sturgeon’s arrest, or speculation about her guilt or otherwise, is of course limited by the laws of contempt. ‘Published items about active cases must not be commentary or analysis of evidence, witnesses or accused’, said a recent tweet from the Crown Office and Procurator Fiscal Service, ‘Contempt is punishable by up to two years in prison and/or an unlimited fine, in serious cases’. In other words: ‘youse have been warned’.

But the reaction inside the SNP to the arrest of the woman who led the SNP over eight years of spectacular electoral success can only be described as incandescent. The succession of arrests has been a hammer blow to the reputation of the Scottish National Party and to the Scottish government, so recently led by the woman who is now helping police with their inquiries. On the day of his most important speech to Holyrood, Humza Yousaf found himself being forced to deny that the SNP is a ‘criminal’ operation.

Scottish nationalists can only hope that the arrest of the former first minister will finally draw a line under a scandal that has dismayed party members, thrilled the opposition parties, and may have fatally damaged the cause of Scottish independence.