Recap #CrimeChat Sept 16, 2013. Today’s #CrimeChat was about real CSI. Retrieving DNA from certain surfaces can be done by swabbing and taping but those methods may not work 100% on porous surfaces, brick, concrete or, wet surfaces. The M-Vac is a wet-vacuum sampling system. Jared Bradley, tweeting as mvacsys, said: “think of a medical […]