A defendant threatened members of the public before slashing his own wrists after being sent down at a magistrates' court.
Douglas MacDonough, of Hemlock Road, East Acton, was sentenced to five months in prison for driving while disqualified last Wednesday (14) when he became aggressive and threatened staff and onlookers, before cutting his wrists with a razor blade.
A police spokesman said the sentence was "the catalyst for the incident."
Members of the public and staff fled the court, in Staines, Surrey, while police raced to the scene and disarmed him using CS spray.
The 36-year-old was detained by officers and his cuts were treated at the scene by paramedics. He was later taken to Wandsworth Prison to begin his sentence.
No one else was injured in the incident and no further charges were brought against him.