<P> Modern practices aimed at curing social ills may run against presumption of innocence . Some civil rights organizations, such as the Canadian Civil Liberties Association consider pre-employment drug testing, while legal, as violating this principle, as potential employees are presumed to be users of illegal drugs, and must prove themselves innocent through the test . Similarly, critics argue that prevailing policies of zero tolerance toward sexual harassment or racial discrimination show a strong presumption of guilt . These dispositions were meant to ease the burden of proof on the victim, since in practice harassment or discrimination practices are hard to prove . </P> <P> Civil rights activists note that the well - meaning practices so adopted may have a deleterious effect on justice being served . An example is the use of a screen in sexual assault cases, which is set up to prevent the complainant from being distressed at the sight of the accused . Where a victim was in fact victimized by the accused, this may be argued to serve the principles of therapeutic justice . </P>

When does the presumption of innocence attach to a criminal suspect