What would you do if you know where a fugitive is hiding?

I have a friend who is running from the cops because he had a warrant for his arrest and was being stopped when he decided to out run the cops. So now they are looking for him for driving while drunk, and driving while barred for life. What should I do? Should I tell the authorities because if he leaves he will put someone in jeopardy of losing his job and he works with the Homeland Security. What would you do?