In modern crimes the period of deposition tends to fall into two categories (i) burials uncovered within the first four weeks of deposition and (ii) those uncovered within five years, but after at least a year of deposition. The depth of deposition appears to be more consistent however. In the UK, clandestine single burials are often, but not exclusively shallow; generally less than 500–600 mm deep . To supplement this assertion, a study of cases within the UK also revealed that the average depth of these graves was 500 mm.