The 10 inmates who broke out of a New Orleans jail in a stunning overnight escape last week used electric hair trimmers with multiple clipper blades to help cut their way through the cell walls, a source with direct knowledge of the investigation told CNN.

The Washington Post investigation published this week reported that New Orleans police were using Project N.O.L.A.'s network of facial recognition cameras to monitor the streets for wanted suspects over the past two years in ways that appeared "out of step" with the local ordinance.