. >> they were mugling in tobacco, marijuana. cellphones. heroin, crack. they were opening grills. in that way they did run a gaol because the cos empowered them. >> u.s. attorney ros rosen stephen oversaw 40 convictions in the constir si. >> a lot of people assume when criminals are put in gaol, you solve the problem by isolating them from the community. gaols have sifts of correction officers, and that creates a security problem. >> how did what happened there inside the gaol affect greater baltimore. >> if you remove gang members. you haven't obviouslied the problem. >> baltimore has one of the highest rates in america, leading to crowded gaols, where prisoners can sort of years before heading to prison, allowing problems to take root. where are we heading? section. >> reporter: this detention center was built behaviour abraham lincoln took action. >> the oldest gaol yes know of. >> reporter: oldest working gaol. pete france is director of maryland corrections. a few years ago the retired city police commander was hired to run the center and realised the corruption went too deep