What is the legal test for issuing an arrest warrant?

Once a warrant is issued, though, it can be subjected to a review. However, sitting in review the judge is not making a de novo determination. Rather, the reviewing judge is only attempting to ascertain whether in law the authorizing judge could have found reasonable grounds existed, not whether the reviewing judge would have found the reasonable grounds existed. As said by LaVigne J. in R v. Libby 2008 NBQB 36: “it is important to remind myself that as the reviewing judge I am not to substitute my view for that of the issuing judge” (at para. 47). A reviewing judge is also cognizant that an authorizing judge is not required to wrestle with the evidence, as in a trial or other contexts, to assess whether the evidence satisfies beyond a reasonable doubt or on a balance of probabilities or makes a prima facie case or establishes a reasonable prospect of conviction. Rather, the threshold standard for the authorizing judge of reasonable grounds translates as to whether there is credibly-based probability for the assertions made by the police. This all leads to the ensuing elaboration.