Wrenches can be used to force open a door- knob. Vices can be used to hold an object. These gripping tools are formed with two surfaces that can be forced together with an object in between. The held object can then be manipulated, but during this pro- cess, marks from the gripping surfaces can be left behind. These markings can be compared to a questioned tool.
Most people are familiar with prying types of tools. These can include pry bars, screw- drivers, and any other flat tool that can be inserted between two surfaces to separate them with the use of force. Their marks can be found in many places. Doors or windows that were pried open are com- mon examples. Crime scene investigators must remember that there are two sides to every tool and must examine the sur- faces with the marks very carefully to make sure they collect all information that may be present.