Question : How can i trace gmail sender IP

Dear experts  
I dont know wether I can i ask this question here.

I am in deep trouble.  Someone stolen my laptop . I have my passport&other important documents in the laptop bag. The thief started negotiating with me through gmail(i guess he got my email  address from the documents). He asked for laptop power on password(BIOS password).he said he would post my documents once he knows the password.

Please someone help me .. how can i trace his ip address ?.I know that  gmail hides the actual sender ipaddress in email headers.

I dont understand how to deal with this situation.

Answer : How can i trace gmail sender IP

Save the emails and notify your local police department and they can move this up to a department that can possibly make the correct calls to find the ip address of the individual. Sadly if the thief is smart he is not using internet access from his home which will make it nearly impossible to find him in a definite manner.
It is very unfortunate when this happens but recovery is unlikely.

 Good Luck.