He was sentenced to six years and three months in prison on Wednesday by a court in Krefeld, North Rhine-Westphalia, for extortion.
The man admitted to carrying out four raids on three banks and one jewellery shop in August and September 2013 to save his own jewellery business in Düsseldorf.
In one unsuccessful raid he left a bag in a bank in Mönchengladbach with the words “Caution, Bomb” written on it. He then phoned the bank and threatened to explode the device if he wasn’t given money, but bank workers called the police and a bomb squad arrived which showed it was a fake.
The court heard one bank employee has been unable to work since as it was the third time the 57-year-old had been the victim of a robbery.
And in Viersen he walked into a jewellery shop with what prosecutors described as a realistic looking gun, which was in fact a toy. But when a customer entered the store he fled empty-handed.
He was caught after a bank raid in Duisburg went wrong. He left an empty drink carton near the crime scene on which police found DNA.
The jeweller escaped on a fold-up bicycle which he pedalled to a nearby car park and then drove off in his black BMW Z3. But a witness saw him escape and police asked all 65 residents of Krefeld with a BMW Z3 for a saliva sample. He was the only one who refused.
Prosecutors called for a nine-year sentence, while his defence team asked for five-and-a-half years.