A man with a lock knife made a 999 call to warn police he was going to kill someone, York magistrates heard.

Martin Butterworth, prosecuting, said Terry Colvin told the control room operator where he was and armed officers went to arrest him.

Colvin now faces a minimum of six months in jail because he has previous convictions for carrying knives in public, Mr Butterworth told magistrates. They committed him to York Crown Court for sentence.

Colvin, 44, of Clarence Street, central York, pleaded guilty to having a lock knife in public. He was released on bail.

His defence team is expected to present details about his mental state at the sentencing hearing on September 22.

Mr Butterworth said CCTV operators alerted by North Yorkshire Police's control room staff spotted Colvin pacing up and down in Clarence Street and helped armed police locate him. The officers found a serrated lock knife on him after they arrested him.