If a Toronto criminal court has served you with a subpoena, you have received a court order , not a polite invitation. You are generally required to attend (or produce what the subpoena demands) until a judge excuses you. Ignoring it can lead to a material-witness warrant, detention, or a contempt finding.
Canadian criminal procedure still uses Latin-rooted terms. When courts determine guilt , they talk about mens rea and actus reus . Subpoena comes from Latin meaning “under penalty”: comply, or face consequences. This article explains what a criminal subpoena is in Ontario, what you must do, what happens if you do not, and when a challenge may be available. It is not a full trial-process guide.
In Canadian criminal law, a subpoena is a court order that compels a person to testify or bring evidence to a proceeding. If you are served in Toronto and are reluctant to comply, get legal advice before you ignore it.
Courts use subpoenas so material evidence is available at trial and related hearings. A judge may issue a subpoena on application by the Crown or the defence. The applicant must show the witness is likely to give material evidence — a subpoena is not a free-ranging fishing expedition for unknown evidence. Subpoenas can also be used for preliminary inquiries, pre-trial motions, and sentencing hearings where witness evidence is required.
Under s. 700 of the Criminal Code , a subpoena requires the person to attend at the stated time and place to give evidence and, if required, to bring anything in their possession or control relating to the proceedings. The person must attend and remain until excused by the court.
In criminal practice, the main functional types are:
Civil “deposition” practice from U.S. television is not the usual Ontario criminal model. If your document talks about questioning outside the courtroom, confirm with counsel what the Ontario order actually requires.
Because a subpoena is a demand, you must comply with its terms if properly served. That usually means:
Court schedules slip. You may not be called on the first listed day. The court can require you to return on a later date. Until you are released from the subpoena, you remain under a legal obligation to attend.
A production-focused subpoena may emphasize delivery of documents by a deadline rather than (or in addition to) lengthy waiting in the courtroom. Read the form carefully and ask counsel if anything is unclear.
If the date conflicts with work, travel, medical care, or caregiving responsibilities, raise it early with counsel or the court office identified on the form — do not simply stay home.
If you fail to attend or remain as required, the court has tools under the Criminal Code to compel compliance.
Under Section 705 (1) , if it is established that the subpoena was properly served and that the person is likely to give material evidence, the court may issue a warrant for the person’s arrest. Related provisions allow the court to detain a witness or release them with or without conditions — including bail conditions — until the evidence is given.
The court may also deal with the failure as contempt under Section 708(1) . On summary disposition under s. 708(2), the person is liable to a fine of not more than $100 , imprisonment for not more than 90 days , or both, and the court may order a further attendance.
These powers are real. “I didn’t want to get involved” is not a defence to a valid subpoena.
A subpoena can sometimes be challenged. In general, the core issue is whether the witness is likely to give material evidence. The Crown or defence may seek to set aside or narrow a subpoena; in some situations a witness may also seek relief. Challenges are often brought in the superior court, though Section 700 (2) confirms the witness must remain unless excused by the presiding judge, justice, or provincial court judge — so practical excuses and scheduling issues are often addressed in the court that issued or is hearing the matter.
Do not assume a challenge will succeed. Get advice quickly if you believe the subpoena is overbroad, improperly served, directed at privileged material, or aimed at evidence that is not material to the issues in the case. Timing matters: waiting until the trial date to raise a problem is usually a worse position than addressing it early.
If you are defending criminal charges and need to compel a witness to provide material testimony or documents, a skilled criminal defence lawyer can assess whether a subpoena application is appropriate and how to frame it.
If you are a witness who has been served and are worried about self-incrimination, scheduling, safety, or relevance, get advice before you simply fail to appear. Counsel can explain your obligations, possible excuses, and whether a formal challenge is realistic.
With more than 30 years of combined experience, Mass Tsang’s GTA criminal defence team regularly deals with witness process issues alongside substantive defence work. For advice about a subpoena you have received — or one you need issued — schedule a free consultation by contacting us today .
