This works well for bite marks, cuts, scratches and scars. This is not a good technique to apply to bruises unless the blood accumulation is very close to the skin surface. UV Photography can be accomplished with an ordinary 35mm SLR if the lens is capable of transmitting light somewhere between 300 nm to 400 nm. The easiest way to make that determination is to place the lens in a spectrophotometer and test it. Most clinical, university or forensic laboratories have one available.
Manufacturers coat most lenses to prevent excess UV penetration.
Excess UV will unbalance a color photograph with excess blue. There isn't a common lens manufacturer that can be recommended. Some lenses will allow UV light transmission down to the 350 nm range and some will not. A simple test in the absence of a spectrophotometer is to photograph someone with freckles. The appearance of freckles in UV light is considerably enhanced compared to standard visible range light photography.