A killer hanged himself in prison just months after his training for freedom programme was stopped when cannabis was found in his bloodstream.
Scott McMillan had served the 13 years punishment part of his life sentence for murder and was on course for release.
But a fatal accident inquiry heard his home leave and work placements were scrapped after he tested positive for cannabis.
McMillan, 43, was found dead in his cell at HMP Shotts, Lanarkshire, in January last year.
Sheriff Douglas Brown was told there were no signs that the prisoner was a suicide risk.
McMillan was jailed for life in 2004 after he was convicted of stabbing Charles “Chuckles” Jack, 29, to death with a screwdriver in Prestonpans, East Lothian.
The inquiry at Hamilton Sheriff Court heard McMillan was locked in his cell shortly before 5pm on January 27 last year after guards checked on him.
At about 7.30am the next day, he was found dead.
Sheriff Brown returned formal findings at the close of the inquiry, saying no other determination was appropriate
