A Forest Bank inmate has been convicted of two counts of conspiracy to rob after plotting armed jewel heists from his cell.
Ian Ogden, 27, was found guilty on Wednesday after a trial at Teeside Crown Court of organising robberies using a number of illicit mobile phones smuggled into prison.
Eight men from Manchester and Teeside have admitted conspiracy to rob.
Masked thieves were caught on CCTV as they snatched high-end Rolex and Breitling watches worth £637,000 from jewellers in Yarm and Middlesborough.
© Cleveland Police
Scenes from the video were played to the court showing four men in black balaclavas trash display cases, fleeing with the high-value items.
Ogden was alleged to be at the heart of the conspiracy, planning both robberies from his jail cell in Liverpool.
He originally denied the charges.
But the gang was scuppered when a stolen Audi getaway car was found nearby with fake numberplates in the boot, and police sourced damning DNA evidence from tools and a crowbar left inside.
Of £515,000-worth of designer watches and £122,000 of stock taken in the robberies only one watch has been recovered.
Ogden is now awaiting sentence.
