A Chinatown grocery store owner will appear in court on Monday to face allegations that he tied up a shoplifter, in a case expected to challenge citizen's arrest laws.

David Chen will appear at Old City Hall for the first day of a trial that is expected to last most of the week.

Chen, 36, was criminally charged by police after he allegedly restrained a man who stole a tray of flowers from outside the Lucky Moose Food Mart in Toronto's Chinatown last year.

Chen and two employees are accused of detaining the shoplifter an hour after the theft, and placing him in a van until police arrived.

Anthony Bennett pleaded guilty to shoplifting last year. He received a reduced sentence to testify in Chen's trial.

Chen and his co-accused face charges of assault and forcible confinement. The Crown dropped charges of kidnapping and carrying a concealed weapon last year.

"Our argument will be that Mr. Chen and his two co-accused were simply defending themselves and their property against a repeat shoplifter, and that is all that happened," defence lawyer Peter Lindsay told CTV News on Sunday.

Lindsay will argue that Canada's laws on citizens' arrest are flawed. The criminal code currently requires that one catch the person in the act of committing a crime.

"That law is too narrow in our view and too restrictive. If, as in this case, you have evidence by video tape that the person committed a crime an hour earlier and you see them back at your store potentially to steal again, you ought to be able to stop them at that point."

Lindsay says police don't have time to respond immediately to every petty theft. In Chen's case, he said he asked Bennett to pay and stopped him when he tried to run away.

"We ought to applaud the actions of Mr. Chen, not put him on trial," he said.

Bennett will be the Crown's star witness in the trial. His sentence was reduced from three months to 30 days as part of his agreement to testify.

Olivia Chow, the area's member of Parliament, has introduced a private member's bill to the House of Commons asking to expand the criminal code.

She called it the Lucky Moose Bill, after Chen's grocery store.

"The Lucky Moose Bill will amend the criminal code to say to the store owners if you are catching them outside the store or within a reasonable amount of time, you won't get charged yourself," Chow told CTV News on Saturday.

"Shop owners who want to defend their own store shouldn't be punished when they try to catch a thief outside the store a few minutes later. That's just not fair."

With a report from CTV Toronto's Austin Delaney