Tech cofounder - what good and bad signs do you look for?

I am looking for technical cofounder to my startups remotely. What good and bad signs should I look for in him? What should be my first steps to check him? If you ask me about programming skills, I was programmer myself, so I may check this. Also - would you consider CEO of software house as cofounder (where he may invest his team) or only independent man? Why?