kill someone

if someone defauld all my money, i go to kill him. i am a murderer. how long will i be sent to the prison. even police arrest him, he will be put into prison only 6-8 years and - 2 over 3. 2-3 years can be free. i am an old man now. i think its the best way after killing him and i commit succide. my family may get my life insurance. this person defauld a lot of people over 10000000 us dollars. of course, i report to police but its not easy to get back the money.