Section 705 of the Criminal Code establishes and governs the court’s power to issue a material witness warrant to arrest an individual who has been properly served with a subpoena but does not attend court.

 In accordance with this provision, the trial judge has discretion to issue a material witness warrant if two pre-conditions have been satisfied:  first, that subpoenas have been properly served on the prospective witnesses, and second, that the person is likely to give material evidence.

CRIMINAL CODE
Section 705

(1)      Where a person who has been served with a subpoena to give evidence in a proceeding does not attend or remain in attendance, the court, judge, justice or provincial court judge before whom that person was required to attend may, if it is established

(a)      that the subpoena has been served in accordance with this Part, and

(b)      that the person is likely to give material evidence,

issue or cause to be issued a warrant in Form 17 for the arrest of that person.

(2)      Where a person who has been bound by a recognizance to attend to give evidence in any proceeding does not attend or does not remain in attendance, the court, judge, justice or provincial court judge before whom that person was bound to attend may issue or cause to be issued a warrant in Form 17 for the arrest of that person.

(3)      A warrant that is issued by a justice or provincial court judge pursuant to subsection (1) or (2) may be executed anywhere in Canada.

 The decision to grant or refuse a material witness warrant is an exercise of the trial judge’s discretion that should not be lightly overturned by an appellate court. It is a question of mixed fact and law.

See R. v. Scott, 1990 CanLII 27 (SCC),  
[1990] 3 S.C.R. 979, at para. 55.

Is the person for whom the warrant is sought “likely to give material evidence”?

 Where counsel makes little or no attempt to demonstrate that a witness’s testimony will be material, it is obvious that courts should not issue a material witness warrant.

See R. v. Kinzie, [1956] O.W.N. 896 (Ont. C.A.); R. v. Darville (1956), 116 C.C.C. 113 (S.C.C.); Foley v. Gares (1989), 1989 CanLII 5134 (SK CA), 53 C.C.C. (3d) 82 (Sask. C.A.); and R. v. Singh (1990), 1990 CanLII 5684 (AB QB), 108 A.R. 233 (Alta. Q.B.).

The Supreme Court of Canada in R. v. Scott, 1990 CanLII 27 (SCC), [1990] 3 S.C.R. 979 (while considering section 698 of the Criminal Code, which is similar to section 705 but which deals with circumstances wherein a person is not likely to appear in response to a subpoena) noted the following:

The material arrest warrant provision is clearly an exceptional remedy.  The consequences of the issuance of a warrant are far more serious for the witness than is the service of a subpoena.  The very liberty of the subject is involved.  It is one thing to attend court in answer to a subpoena.  The subpoenaed witness may feel compelled to attend but attends by an act of his or her own will.  It is quite another to be picked up by the police and escorted to the courtroom.  The issuance of the warrant should therefore be subject to careful consideration when an application is made to the trial judge for its issuance.  It is appropriate and indeed essential that the trial judge undertake a new inquiry into the materiality of the potential evidence to determine whether or not the warrant should be issued.

 While the Court must be convinced that a witness is likely to provide material evidence, counsel does not need to prove that a witness will testify as anticipated.  The standard is one of a balance of probabilities

R. v. Pereira et al, 2006 BCSC 1720 (CanLII).

 The justice may choose not to insist upon evidence on oath but he may want to conduct an oral examination, if only a cursory one, of some person who has knowledge of the circumstances. The extent of such an examination will depend on the circumstances of each situation.

Foley v. Gares(1989), 1989 CanLII 5134 (SK CA), 53 C.C.C. (3d) 82 (Sask. C.A.) – the Court discussing the standard of inquiry required for section 698 warrants.

 Courts must balance individual freedoms against the needs of justice and the justice system, aware of the fact that these applications are almost invariably heard without response from those whose liberties are directly affected.

R. v. Pereira et al, 2006 BCSC 1720 (CanLII).