NY civil rights laws regarding arrest of shoplifter

Unlawfull proceedure when arresting an accused shoplifter: Hello,
I was recently arrested for petit larceny amounting to 11 dollars and I thing that the procedure used by the security was wrongfully done. I was still in the store when a man not wearing uniform grabbed me by the arm and led me to the beack of the store when the door was shut and me and the security worker waited for the police to arriuve. During this time he asked me my name and I replied he did not belive me so he demanded that I give him my purse, so I did. Then he searched through it and looked for my ID and when he did find it the name that I told him and the name on my ID did in fact match. Furthermore he continually scared me by saying that I was going to jail for a long time because I had stoled 11 dollars in sugar and flour! I think that many of the steps that this employee took were illegal. This is my first offense and I dont want it to be on my record. Should I get a lawyer? pLEASE HELP i DONT HAVE A CLUE WHAT TO DO?? - Is this your question? Add additional information