Canadian Criminal Procedure and Practice/Trials/Role of Trial Judge
Powers and Responsibilities of the JudgeEdit
An accused person is entitled to a Constitutional right to an impartial trier-of-fact.
Once a judge begins hearing evidence and makes a ruling on it, the judge becomes seized with the matter and no other judge can take over.
See s. 11(d) of the Charter which is the right "...to be presumed innocent until proven guilty according to law in a fair and public hearing by an independent and impartial tribunal;"
See also R. v. Valente (1985), 23 C.C.C. (3d) 193 (S.C.C.)
R. v. Campbell (1997), 118 C.C.C. (3d) 193 (S.C.C.)
- R. v. Curtis,  66 C.C.C. (3d) 156 (Ont. Gen. Div.)
A Superior Court Justice has the inherent jurisdiction to eliminate any procedural unfairness that arises during a trial.
The "procedural directions contained in the Code are of necessity exhaustive". The powers of a provincial court judge are "entirely statutory." However, "the authority to control the court's process and oversee the conduct of counsel is necessarily implied in the grant of power to function as a court of law. This Court has affirmed that courts can apply a ‘doctrine of jurisdiction by necessary implication’ when determining the powers of a statutory tribunal.” 
The inherent powers of a superior court judge to control the court process is said to be equally available to provincial court judges either expressly by statute or by necessary implication.
Consequently, a provincial court judge has implied jurisdiction to "vary one of its own orders in order to correct clerical mistakes or errors arising from an accidental slip or omission or in order to properly reflect the intention of the court"
Generally, a "court has a limited power to reconsider and vary its judgment disposing of the case as long as the court is not functus.”
- R. v. Rose,  3 S.C.R. 262 1998 CanLII 768
- R. v. Doyle 1976 CanLII 11 (SCC),  1 S.C.R. 597
- R. v. Cunningham,  S.C.R. 331 at para 19
- R vs Doyle 1976 CanLII 11 (SCC),  1 SCR 597, per Ritchie, J. ("Whatever inherent powers may be possessed by a superior court judge in controlling the process of his own Court, it is my opinion that the powers and functions of a magistrate acting under the Criminal Code are circumscribed by the provisions of that statute and must be found to have been thereby conferred either expressly or by necessary implication.")
- see R. v. Rhingo,  O.J. No. 1110 (Ont. C.A.) and R. v. Robichaud,  N.B.J. No. 175 (C.A.)
- R. v. Adams, 1995 CanLII 56 (SCC),  4 S.C.R. 707, at para 29
The judge is required to listen to evidence that "advances the work of the court". He or she cannot be required to listen to irrelevant or pointless evidence. The judge may even disallow the submission of non-relevant evidence.
The judge has an obligation to track the admission of evidence to ensure that the record is restricted to what is admissible, and also that it is only used for the purpose for which it was admitted.
The judge has the jurisdiction to edit the evidence, including written statements and oral testimony, as it is given. The judge may edit out portions of the evidence that is prejudicial or otherwise irrelevant or immaterial only so long as it does not distort the probative evidence.
Evidence before a judge are not facts. The judge has the power to hear evidence from which factual conclusions may be made. The Judge may make inferences. These inferences must be logical conclusions drawn from the evidence before the judge at trial. They cannot be conjecture or speculation about potential evidence that has not be submitted before the court.
There are generally well known inferences, that a judge will make regularly such as the inference "that one intends the natural consequences of one’s actions [in] any ... human activity, especially in light of the lack of evidence to rebut the inference."
- Caswell v Powell Duffryn Associated Collieries Ltd  3 All ER 722
- R.v. Missions 2005 NSCA 82 at 21
Sitting Position of AccusedEdit
Sitting arrangment of the accused in the court is in the sole discretion of the trial judge.
Custom dictates that the accused is to be placed in the dock which is not said to violate the accused’s Charter rights.
The jury should be able to see the accused during the trial. This interest may prevent the accused from requesting a seat at counsel table to give instructions.
Judge Following a CaseEdit
Once a judge hears evidence or facts on a case they are seized with the case and must follow the matter to its conclusion.
Where a judge falls ill, they remain seized with the matter unless there is unreasonable delay that results.
- R. v. Brown, 2012 ONSC 822
Doctrine of Functus OfficioEdit
A judge has jurisdiction over an outstanding charge up to the point where the charge has been resolved by way of a stay, withdraw, dismissal, acquittal, or sentencing. The doctrine of functus officio refers to the principle that a court no longer has jurisdiction to change any decisions once a charge has reached its ultimate conclusion.
This common law rule states that the final judgement of a court cannot be reopened.  The power to review a decision is transferred by the Judicature Act to the appellate division.
This rule only applies to judgements that have been drawn up, issued and entered.
It is said that a court is functus if and only if "the duties and functions of the [court’s] original commission have been fully accomplished"
There are exceptions to this rule. The court may still interfere with a prior decision where:
- where there had been a slip in drawing it up, and,
- where there was an error in expressing the manifest intention of the court
A trial judge sitting without a jury is functus officio only after he has imposed his sentence.
An intermittent jail sentence cannot be varied by the sentencing court to a non-intermittent. There is some authority suggesting that the court may vary the entry and exit times of the intermittent sentence based on the power of the court to control its own process.
originates from Re St. Nazaire Co. (1879), 12 Ch. D. 88
- Chandler v. Alberta association of architects, 1989 CanLII 41 (SCC),  2 SCR 848
- Jacobs Catalytic Ltd. vs International Brotherhood of Electrical Workers, Local #353 2009 ONCA 749; 312 DLR (4th) 250 at para. 60
- Chandler v. Alberta association of architects, supra
- R. v. MacDonald 1991 CanLII 2424 (NS CA), (1991), 107 N.S.R. (2d) 374
R v. Germaine (1980) 39 NSR (2d) 177 at para. 5 - no jurisdiction to make intermittent to non-intermittent because not in text of 732
R v Jules  BCJ 1605
R. v. E.K., 2012 BCPC 132
c.f. R. v. Crocker, 2012 CanLII 42379 (NL PC)
Communications with Counsel Out of CourtEdit
Ex parte communications (i.e. communications in absence of one of the parties) concerning an ongoing proceedings should be avoided. It is a rule that relates to the "public perception of fairness within the administration of justice".  It also preserves "confidence of the public in the impartiality of the judiciary and thereby in the administration of justice".
Ex parte communications between judge and counsel concerning a case will "almost invariably raise a reasonable apprehension of bias".
- R. v. Deleary, 2007 CanLII 71720 (ON SC) at para. 22
- R v Jones, 1996 CanLII 8006 (ON SC), (1996), 107 C.C.C. (3d) 517 (Ont. G.D.)
- Jones and Deleary
Intervention During TrialEdit
There is a presumption that a trial judge has intervened in a trial properly. The judge may often make comments, give directions or ask questions.  The key issue is whether the intervention affected trial fairness.  This is from the perspective of a reasonable observer. 
A judge may disrupt questioning in order to clear evidentiary ambiguities, pursue subjects left vague by the witness, and ask questions counsel should have asked.
"Interlocutory remarks" of the judge during argument are not "judicial pronouncements"
A judge is permitted to give the jury mid-trial instructions to disregard any erroneous comments made by counsel. If it is given promptly and with explanation of why it should be disregarded, this can effectively correct any concern that a jury might misuse the information. 
There is a presumption that an accused not be restrained while in court. It is upon the Crown to establish grounds to order the restaint of the accused.
Unnecessary and repeated interruptions that disrupt the flow and effectiveness of cross-examination may exceed permissible limits.
- Chippewas of Mnjikaning First Nation v. Chiefs of Ontario, 2010 ONCA 47, at para. 231
- R. v. Valley 1996 (Ont. c.A.)
- R. v. Stucky 2009 ONCA 151
- R. v. Watson, 2004 CanLII 45443 (ON CA) at para. 10
- R. v. Visscher, 2012 BCCA 290 (CanLII) at para. 25
- see R. v. Normand (D.G.), 2002 MBCA 95 at para. 20, 166 Man.R. (2d) 179)
- R. v. W.H.A., 2011 NSSC 166
- R v Watson
Exclusion of partiesEdit
The trial judge can order the exclusion of the accused where his conduct makes the proceedings impractical.
The accused can likewise voluntarily be absent from the trial with the court's consent. However, depending on how the proceedings go in the absence of the accused, there may be a ground of appeal.
Preserving order in court
484. Every judge or provincial court judge has the same power and authority to preserve order in a court over which he presides as may be exercised by the superior court of criminal jurisdiction of the province during the sittings thereof.
R.S., 1985, c. C-46, s. 484; R.S., 1985, c. 27 (1st Supp.), s. 203.
The judge does not have the power to order that counsel not communicate with a witness who is not in the middle of testimony. The rules of contempt of court and Professional Conduct are the only limitations on counsel's right to speak with witnesses and clients in court.
- R. v. Arsenault, (1956) 115 CCC 400 (NBCA)