Is There a Twin?

If you're like a premeditated criminal, then you can plan things like creating alibis to try to commit the act within a very short timeframe. Why aren't there more murderous identical twins? It just struck me. I'm going to have a twin and keep my twin a secret for 27 years. Then on my 28th birthday, I shall commit the perfect crime. Maybe if you move to another country with your twin and kept them a secret, maybe there's a way to do that.