no criminal record. Can you obtain for me since i will never go back to China?

hi !i worked in Shanghai for 8 years and came back home for good last january 2015 and processing my US spousal visa ,never thought i need to obtain police clearance and one of the requirements for US embassy. it possible if my friend can process ony behalf?or can you give a note or letter if they couldnt obtain one for me.please advice.
Mar