Are excessive traffic fines and debtors' jails fuelling community tensions in suburban Missouri? Claire Bolderson reports on a network of ninety separate cities in St Louis County, most of which have their own courts and police forces. Critics say that their size makes them financially unviable and allege that some of them boost their incomes by fining their own citizens and locking them up when they can't pay.

This edition of Crossing Continents goes out and about in St Louis County to meet the people who say they are victims of a system which sees arrest warrants issued for relatively minor misdemeanours. Many of the victims are poor and black. The programme also takes us into the courts, and out onto the freeways with some of the County's police, who say they are upholding the law and promoting road safety.

The US government is not so sure. One of the towns in question is Ferguson where riots erupted after a white police officer shot a young black man dead last summer. In a recent report on the riots, the Department of Justice concluded that the Ferguson police had been stopping people for no good reason. It said they were putting revenue before public safety.

Claire Bolderson investigates how widespread the practice is and considers the impact on relations between citizens and the authorities that govern them.

Produced by Michael Gallagher.