[2] Born in Edinburgh, Bain attended the University of Aberdeen School of Law, graduating with an LLB and a Diploma in Legal Practice.

First Minister Nicola Sturgeon nominated Bain for Lord Advocate and on 22 June 2021 she was sworn into office at the Court of Session with Ruth Charteris KC, Solicitor General.

[5] Completing her traineeship with TF Reid & Donaldson, a law firm in Paisley, Bain was still unsure of where she wanted to take her legal career.

She also represented the petitioner in a petition to the Nobile Officium of the High Court of Justiciary which held that where an accused person in criminal proceedings seeks to admit evidence of sexual history, the complainer must be told of the content of the application; invited to comment on the accuracy of any allegations within it; and be asked to state any objections which they might have to the granting of the application.

[14] On 16 June 2021, it was announced that Bain would be nominated by Nicola Sturgeon, subject to the approval of the Scottish Parliament, to take up office as Lord Advocate, succeeding James Wolffe.

[25] Addressing the Supreme Court, Bain advocated that she believes that it "would be in the public's interest that clarity be brought about the scope of the Scottish Parliament's powers in respect to this issue" (the holding of a legally binding second independence referendum).

[30] Bain told MSPs: "I have considered the review and I have decided that an extension of the recorded police warning guidelines to include possession offences for Class A drugs is appropriate.

"[31][32] Many opposition parties argued against the law change, highlighting cities across Scotland, including Dundee, where "communities are devastated by the failures of the 'war on drugs' approach".

"[33] In November 2021, Bain told the Scottish Parliament's justice committee, she would consider a "precise and specific" proposal for drugs consumption rooms in Scotland.

Her predecessor, James Wolffe, ruled out the idea of consumption rooms where drug users could take illegal substances in supervised conditions.

[36][37] The following month, Sturgeon announced the referendum would be held on 19 October 2023 and sought the Prime Minister's consent to the vote by the granting of a section 30 order, a move that Downing Street rejected.

[43][44] From 21 May 2020, Bain, as Lord Advocate, directed that any death in Scotland, either confirmed or expected, from the COVID-19 pandemic be reported to the Crown and Procurator Fiscal Service.

[45] Bain established Operation Koper in her role as Lord Advocate, serving as the head of the systems of prosecution and investigation of deaths in Scotland.

[47] As Lord Advocate, Bain changed the system for the way deaths relating to Covid-19 were required to be reported in Scottish care homes under Operation Koper.

[48] In January 2024, it was revealed that Bain could be brought forward by the Scottish Parliament for questioning relating to the wrongful prosecution of up to 100 Post Office branch managers in Scotland as part of the horizon scandal.

First Minister Humza Yousaf told the Scottish Parliament on 11 January 2024 that after speaking with Bain, she was "more than happy to consider whether it was a briefing or whether it was a ministerial statement".

In a statement, Bain said "because of its fundamental and sustained failures in connection with Horizon cases in Scotland, I've decided that Post Office Limited is not fit to be a specialist reporting agency".

In January 2024, SNP MP Joanna Cherry KC introduced a private members bill in the House of Commons that would allow for powers to be given to the Scottish Parliament to reform the Lord Advocate's role.

malicious prosecution scandal and the ongoing investigation into SNP finances" as examples as to why such accusations could be made given the Lord Advocate's current role within the Scottish Government as its chief legal adviser.