They still don't. Maybe you'll marry, maybe you won't. Maybe you'll have children, maybe you won't. Maybe you'll be caught red-handed in your bloody charnel house surrounded by the remains of your victims, maybe you won't. Whatever you do, don't congratulate yourself too much, or berate yourself either.
Police work is half chance.
So is homicidal mania. Or someone else's body. Use it every way you can. Don't be afraid of it or of what other people think of it. You can always get rid of the witnesses later.