The allure of the seemingly infallible forensic sciences in popular entertainment may lead to unrealistic expectations as to the nature and sufficiency of the evidence the prosecution requires to secure a criminal conviction.
While the prosecution bears the heavy burden of proving an allegation beyond a reasonable doubt, the prosecution is not required to produce forensic evidence, nor prove an accused's guilt to a standard of indisputable, absolute certainty (R. v. Lifchus,  3 S.C.R. at para. 39).
For example, many individuals are surprised to learn that they may be convicted based solely on the testimony of one compelling witness for the prosecution without any other corroborating evidence (R. v. G.(A.),  1 S.C.R. 439, at para. 30).
There is often no definitive way to reconstruct past events with forensic evidence and the constitution does not hold the prosecution to that impossibly high standard of proof. The reality is that the justice system relies heavily on the oral testimony of witnesses to recreate the past at a criminal trial – conclusive forensic evidence of an accused’s guilt is exceptional in nature.