Since one of the most accurate methods of proving a case in court is through the scientific evidence obtained through tests made at scientific labs for things like DNA and toxicology reports. Even though the Ottawa criminal lawyer representing a person may have access to all the same reports as the defense, it's very often difficult to argue against the scientific certainty that DNA evidence often provides. It has become standard practice that a lawyer will investigate heavily the chain of evidence to see if there have been any mistakes made during testing because incorrect practices can lead to evidence being thrown out.