D was charged with aiding and abetting another to commit both unarmed robbery, and extortion, and with conspiracy to commit both offenses. A Peggie Johnson was approached by a man, subsequently identified as Edward Kimble, who handed her a note threatening her three sons unless she gave him money. According to her testimony at D's trial, she complied with the demand because she feared for her own safety and that of her children. Mrs. Johnson also testified that she had never seen Edward Kimble before the robbery, but that she knew D well and regarded him as a family friend. Further, she indicated that approximately one or two months before the robbery, D stopped in at the Consumers Power Company office and '[questioned] us about the lunch hours.' Kimble and his girlfriend, Diane Potter, were arrested the day after the robbery while shopping at a J. C. Penney. Potter's identification of D at a photographic show up approximately three weeks later led to D's arrest. Kimble pled guilty to unarmed robbery and received a 5-1/2- to 15-year sentence. He indicated that he first met D, who he knew only as 'Hank,' at Jackson Prison, where he was serving a sentence for armed robbery and D was employed as a prison guard. He again came into contact with D in November of 1975 at Leake's Lounge. Kimble testified further that he and D discussed the 'Consumers Power job' on the afternoon of December 18. D wrote the threatening note that was to be presented to Peggie Johnson; and that Potter copied the note because D was afraid the victim would recognize his handwriting. After getting the money, Kimble testified that he then met d and gave the money to him at a place called 'the roller room.' They then divided the money in Kimble's hotel room. Potter verified Kimble's versions of the events. D denied any involvement in the crime and presented an alibi defense. The jury returned a verdict of guilty on all four counts. D was sentenced to 7-1/2 to 15 years with credit for 189 days on the unarmed robbery and conspiracy to commit unarmed robbery convictions and to 7-1/2 to 20 years with credit for 189 days on the extortion and conspiracy to commit extortion convictions, with all four sentences to be served concurrently. The Court of Appeals affirmed D's convictions of extortion and conspiracy to commit extortion, but reversed, as violative of the proscription against double jeopardy, US Const, Am V; Const 1963, art 1, § 15, the convictions of unarmed robbery and conspiracy to commit unarmed robbery. D appealed.