I was once arrested for a taking stuffs less than 30$. I was given a ticket by a police for just Trespassing. No court date or anything, not a theft under 5000 charge.
Today I made a another but vey small mistake. I open a package of screen protector costing about 11$. I opened it, took one piece to check it. Deciding I don't want to buy it, I put back the whole package, but still had the one piece in my hand. I was arrested outside for taking that one piece of small plastic protector with me which I forgot to throw away.
They call the police and police charged me for theft under 5000, stating that I have a warning before.
My question is, will that tresspassing ticket handed to me 3 years ago will also affect my charges today in court? As it was not a theft charged?
Will be eligible for diversion as it was my first offence of theft under 5000? Please help, any ideas will be greatly appreciated.

It should have an effect, if it was a ticket and you paid a fine, since you had that as your first conviction. First offender is not per crime but reflects any crime.

I would get an attorney at this point.

Thank you Chuck. I called one criminal lawyer today. He said I don`t need a lawyer. He said, the crown would not ask about the previous ticket, as they will only deal with the present charges which is very small. He also said that the crown will only ask if I am willing to give any donation.
I am relieved, but still worried. I wanted to call a few more lawyers. Thank for your advice, I greatly appreciate it.

It is a minor thing, the crown will have a record of the other ticket but not sure how they will effect it. But again, yes, minor fine at most ( my opinion)