http://soscanada2000.com/polclerfromu.html
Just call the numbers listed in this webpage, and find out the procedure to get your records. That is just what I did.
You can not get 未犯罪公证 from USA to show you have no criminal record in China. You have to do it in China. And you can not get your birth certificate in USA either, unless you were born here. Send photocopy of your passport back to China. Ask your friends in China to take it and your Identification Card (Shen Feng Zhen) to a local Notarization Service Department. Then you will get the birth certificate and 未犯罪公证 from China.