Deception may not be their intention, but witnesses in criminal cases are not always reliable. As time passes, memory fades or becomes a distortion of the actual event, and often people develop inaccurate reconstructions that could potentially lead to the conviction of the accused. Witnesses may also be susceptible to undue influence from police officers and prosecutors, and cross-examination by a criminal defence lawyer is needed to arrive at the facts of the matter.A judge in Toronto recently found inconsistencies in witness accounts of an alleged assault in a shopping mall. The defendant, a young man from South Sudan, was jailed for seven months prior to his trial. He was accused of shoving an elderly woman down a staircase, but surveillance video of the incident in question led to his exoneration.Two witnesses claimed they saw the young man push the woman down the steps. The elderly woman also testified that she was pushed. However, closed-circuit video showed the man's hand gesturing in a way that appeared to indicate that the woman could pass. The man also testified through a translator that his split-second contact with the woman was inadvertent.According to the judge, the man's gesture "appears like nothing so much as an offer of physical guidance, direction or support." The judge went on to express "profound concern" that the Crown proceeded with the prosecution despite being in possession of "factually exculpatory evidence" -- the video -- for months.The Toronto Star has more on the witness statements which the judge found to be inconsistent with the video evidence.To proceed with prosecution in a criminal case, the Crown must have a reasonable expectation of a conviction, and proceeding with the prosecution must be in the public interest. Through early intervention, a criminal defence lawyer may be able to show that the Crown's case meets neither of these criteria.