A drug user robbed staff at a city store at knifepoint and then sat outside to wait for the police, a court heard.Desperate Dean Tyrrell, aged 29, wanted to go to jail so that he could be treated for his drink and drugs habits.He threatened a sales assistant and a manager at the Tesco Express until they handed over some cigarettes and a lighter, Plymouth Crown Court heard.But Tyrell then told the man and a woman: "You can call the police now. I will be sitting on the steps...
