i have been asked to invest money in a restaurant?

ok here is the skinny.my brother is look n to open a restaurant.
and ask me to invest. he has been in the business a long time and he knows it well.he has opened several and has failed . i feel the reason he has failed is does does peaple wrong he gets greedy doesn’t pay the bills
i will give you a few details
the last time he asked my dad for money .business was doing very well
or at least that what he told me.he was always at the golf course always had a few friends with him getting drunk.
He always come to my house and brag and put me down.
i told be careful because what goes up must come down. well fast forward a few months. he never pad my dad he lost his restaurant
he had to move in with me cause he had nowhere to go.
he began to recieve letters from food venders he owed money.The IRS
labor department where he didnt pay his peaple. he filed a police report
that some broke in to the safe and stole money and tried to collect
insurance . which later he was charged for for.
Its a shame but my mom and i think the same about him he will try to
screw any one around if has chance to make money off them.
He could not pay me rent but he drove a jag and always had his clothes pressed
I have kept tellin him do the right thing,Karma, what you sow is what you reep be humble work and don’t look for the fast buck.what you put out comes back. put out bad and bad comes right back.Any way enough with the details. He asked me to invest some money in a resturant. i first thing i told him is i cant trust you.
but i believe if he applies him self he can make successful.
So my ques is how do i protect my self and make sure every thing is on the up and up. contract lawyer,accountant, bussines lawyer?
He mentioned he would give me a good return on my money
Time out i dont want good return can go buy a CD at the bank and get secure return i want to be part owner what do i do i really would like for my wife and i to qiut our 9to5 have something that can be ours
HELP PLEASE?
what percentage do i own depending on how much i put in? how much is it worth?
can accountant tell me or business lawyer?
i have to protect my investment there has to be a contract

You more or less answered you own question. If you invest with your brother, you will have to spend just about all your time in that restaurant because he won’t. Sure he could change and finally learn from experience, but I would not want to have to find out the hard way that he is still the same irresponsible playboy as before.