It may cost you, but the bank should be able to pull ALL statements and activity from this account from their archives.
In business, I have had to deal with difficult people in the past, think twice about the registered letter. They have to sign for it, and they can reject the letter, and not sign.. so you get your $6.00 ( about that in postage for registered/return receipt) letter returned and you are even MORE angry and frustrated.
I would say that this is on the verge of requiring legal action. More than likely your Bylaws state that the Treasurer has the responsibility to maintain all financial records and to provide them to any Director or board member if requested. She is breaking this rule, for reasons as yet unknown.
The scare tactic may be your best avenue. A local lawyer may be willing to donate their time to write up a letter demanding proper turnover, or you may need to pay for this service.
There is obviously more to this story than what is being presented though. Is she being suspected of any wrong doing? Has she been accused? I'm just wondering why she is taking the stance that she is.
In regards to just closing the existing and opening a new account, that may not be the best route. Last year's President will be responsible for any issues down the road. The Treasurer would be as well, but an audit must be performed at this time. If she no longer has access to the account then you can probably keep it as is. Though overall I would recommend forcing the situation so that you can perform a correct audit. One possible avenue is to have an accountant perform an audit "at the demand of the Principal". She may put up resistance to you guys but may back down in the face of the Principal/Superintendant or School Board.
You might have something there beignets! There are definitely record retention requirements for financial records with the IRS. I would be tempted to give a call to their help line just to see what they might recommend. At the very least it may give you some additional legal requirements/info you could include in your communication with this treasurer.
i wonder it the irs, 501c3 dept, 1-800 nr, could help you?
501c3 are bound by certain disclosure rules, and shredding documents by a past officer is not something that probably would fit the rules under which you are supposed to operate. maybe they can give you some free advice over the phone.....
in any event, sounds like registered letter (return receipt requested) to the past treas is GREAT ADVICE. document, document, document. i would copy the principal and super (not registered) on any such correspondence, so she knows they are being informed. doesnt matter that you are independent, you can cc them anyway, you are 'working' for their school.
If they don't already know, I would notify all of your board members of the situation and bring the principal in too. Get out your bylaws and see what they say in relation to the Treasurer's duties and financial controls. Highlight any areas relevant to the current situation. Make a copy of those pages of your bylaws and send them to the treasurer with a registered letter requesting the immediate turnover of all financial records to a designated board member or the principal. Give her a date and time that the records must be turned over(in whole and intact). Close that account immediately and move all funds to another account. If she doesn't respond, I'd be looking for some legal help.
It certainly sounds like she has something to hide. If you and your fellow board members are making a concerted and professional effort to retrieve the records and protect what money remains, I can't see that you would be held responsible for any wrongdoing on the part of the treasurer.
I don't have the answers to your questions (new at this myself) but as a treasurer, I can't think of any reason that she would feel justified in not giving any other officer any information they request. They are OPEN books. I don't understand why your treasurer would even consider shredding anything. I would be very concerned about this situation. Something doesn't sit well here. Sounds to me like you are doing the right thing by trying to get the PTO funds out of her hands.