appeal a ticket...? please help

Hi, my son is 19 years old. He went into a supermarket I know for a fact he left the house with 3 cans in his bag. He went in with those inside his side bag, and upon entering the store none of the employees confiscated his bag. He was stopped on the way out of the supermarket after paying for the groceries by the security who was very rough, and pulled on his arms and nearly dragged him to the backroom of the place. He was held there for 2 hours waiting for police. There seem to be no cameras in any of the aisles except for the 2 first ones of the store, and there was no evidence to prove that my son indeed did steal from the super market. However he was given a ticket by the police officer for trespassing of property as well as another ticket due to the fact that the address on his drivers license had not been changed yet. (We moved 2 months ago to Ottawa) My son never keeps receipts, neither does anyone in the family most of the time, so there is no proof to show that the cans were purchased. Also aside from ill treatment received from security guard the officer who issued the tickets check marked stating that there was a vehicle involved when in fact there was not. My son's car is broken and has not been driven for about 50 days now. What can be done about this? I contacted a lawyer who said he could appeal it in court, and although there have never been any incidents in which my son has been involved with shoplifting, but as a safety precaution I would like to know if in fact he "had" stolen from the supermarket the ticket is appealed and he is found guilty, would he have worse consequences then that of a ticket. Would they be able to charge him?
This entire even has been very strange, the officer's signatures are different in each ticket, my son tells me he was not wearing his hat ( not sure whether that is relevant) and the officer "confiscated" some of my son's personal items and told him they were for his "private inventory". My son was banned from the mall, in front of his place of employment where he makes daily trip to for food etc... but was never asked to sign the notice that he was banned. This is all very strange, and it does not make any sense, can someone shed some light please?
Thank You