Henry John Burnett (5 January 1942 – 15 August 1963) was the last man to be hanged in Scotland, and the first in Aberdeen since 1891. He was tried at the high court in Aberdeen from 23–25 July 1963 for the murder of merchant seaman Thomas Guyan. His execution, at HM Prison Craiginches Prison, Aberdeen, was performed by hangman Harry Allen.
On 2 February 1957, Thomas Guyan married Margaret May, and a year later they moved into a first floor flat at 14 Jackson Terrace, Aberdeen, a house owned by May's grandmother Annie Henderson.
A son was born in September 1958, followed by a second in February 1961; however, the father of this second child was not Thomas. This led to marital problems which came to a head in 1962 when Margaret consulted a solicitor about the possibility of a divorce which her husband refused. Then, in December of that same year she went to work at John R. Stephen Fish Curers where she met a new admirer, Henry Burnett.
A relationship soon developed and, by May 1963, Margaret had moved out of Jackson Terrace with her younger son Keith to share a new address in Skene Terrace with Burnett.
Henry Burnett came to believe that, given the chance, Margaret would leave him, so he took to locking her in the house whenever he went out. This was not a state of affairs which Margaret relished so when by chance she met her estranged husband on 31 May, she agreed to go back to him.
Margaret Guyan arrived at 40 Skene Terrace at 4.00 pm, to collect her son Keith. A family friend, Georgina Cattanagh, went with her for moral support. As soon as Margaret announced her intention to go back to her husband, Burnett cried "Margaret, Margaret, you are not going to leave me!" He then drew a knife to Margaret's throat, closing the door behind them.
Fearful of what was happening inside, Cattanagh banged repeatedly on the front door and demanded the release of Margaret. Minutes later, Burnett threw open the door and ran off down the street. Margaret was shaken, but relatively unhurt. The two women made their way back to 14 Jackson Terrace.
Burnett went to his brother Frank's workplace and told him what had happened; his brother urged him to go to the police. But Burnett, still set on revenge, instead went to Frank's house in the city's Bridge of Don area to borrow his brother's shotgun. Because Frank's wife had been told never to lend the gun to anyone, Burnett forced the cabinet open and stole the gun, along with some cartridges, after which he boarded a bus to 14 Jackson Terrace.