Ross v HM Advocate 1991 JC 210 is a leading Scots criminal case that concerns automatism as defence.

[1][2] The High Court of Justiciary clarified the rules for an accused to successfully argue automatism as a defence to a criminal charge.

Thirty minutes after having consumed the drink, he started screaming and indiscriminately attacking other people with a knife.

He argued that the trial judge had misdirected the jury by telling them that they could not acquit Ross of the offences, in spite of his involuntary intoxication.

[3] The Lord Justice-General Hope identified three requirements for automatism:[3] Later cases suggested that the Scottish precedent established in Ross would be followed in England as well.