To get insurance on someone you need an insurable interest. Typically a spouse or a dependent of the applicant would have lost something if he died has an insurable interest. Otherwise people could buy a policy on a guy and kill the insured. In any event, with AIDS etc. every insurance company underwrites every applicant for any significant amount of insurance -- and the guy would have to sign a medical form and take a physical and blood test, and may be uninsurable. On the other hand, while you probably couldn’t buy an insurance policy from the insurer because you don’t have an insurable interest, you could buy a person’s interest in benefits under the policy. Obviously, this would all be much easier if your friend knew you were doing it and was willing to cooperate.