A Scottish man released from prison after spending two decades on Ohio's death row is heading back to prison.

Ken Richey was sentenced on Monday to three years for threatening a judge who prosecuted his original case.

Richey pleaded guilty to a felony retaliation charge last month. He admitted he had been drinking heavily before he left a threatening phone message from his Mississippi home last New Year's Eve.

Richey was on death row for 21 years after being convicted of starting a fire that killed a two-year-old girl in 1986.

A US court determined his lawyers mishandled the case, and he was set free in 2008 under a plea deal.