Always paying for stepson's mistakes

Hi all, Step son was detained for shoplifting a $12 shirt from Kmart. He paid for the shirt after confronted. We were called...dad was on duty and I told them to arrest him if he commited a crime. He is a bit of a handful. Kamrt told us they would release him since they dont prosecute on anything under a certain dollar amount. Nothing was mentioned about civil case. Received letter in the mail this week that they want $625 in ten days or off to court we go. The amount is much higher than what I have read on this site. I researched the 'law firm' which seems to be a collection agency that has a lawyer on retainer. First, I have a problem paying the amount consider that he paid for the shirt. Second, under California penal code 490.5 the amount isnt to be less than fifty or more than five hundred. So why such a high amount?
So, I have read of you all paying the demands of these letters, but have any of you not paid? Have any of you been actually pursued in court? I am seeking the advice of our family attorney tomorrow, so I will keep you posted. They dont have my SSN or my husbands so I cant see how it could affect our credit (unless, of course, it goes to court). Have any of you negotiated down the amount (for California)? We spoke to the office and they will reduce by 15% if we pay in full....thats not good enough, frankly....want it to disappear without my checkbook disappearing with it. Cant wait for this kid to turn 18! Thanks for your advice!

Thought I would update even tho there arnt any replies (are you all shy all of a sudden?)
Our attorney said that the 'law firm' is more of a collection agency with one attorney per some thirty or forty collection agents. She advised us to have them itemize what the damages are for the huge amount. A resonable amount to negoiate for the 12 buck shirt should be no more than 200 bucks and that is on the high side. Her attitude was to blow it off since they dont have our social security numbers to screw our credit with and chances are that they wont pursue a case in court since we have an attorney on file (although not retained yet) She told us to forward her name and number and let them play ball.
So what do you all think? We are taking the weekend to 'sleep on it' but want to know what you all think.

I think it's a bit extreme for the shirt, also a good idea to sleep on it. I don't deal with civil demands on my current job but I inclined to agree with the 'blow it off' approach.....but you'd better check with your lawyer first to be safe. Another thought, if the kid screwed the pooch.....let him pay it, time to learn those hard lessons.

Our attorney is sending a letter to the Kmart attorneys to settle case. Both the attorney and ourselves agree that we shouldnt pay more than 200 for the event. Kmart itemized the charges that they are going for the full 500, per the penal code and 125 for the attorney fees.
We are, in a sense, blowing the letter off. They dont have our social security number so it wont be apprearing on our TRW unless it goes to court. Our attorney has advised us to sit back and wait. She has sent the letter, now we will just give it some time. If they decide to proceed with court, we can either pay in fear of losing or fight like hell.
I agree with you that the kid should pay for all damages. He has since aquired a job and will be paying for this crap.