Should I beat the thief?

Last night I caught a thief in my house but he looks so innocent that my heart really got melt. now I have changed my mind and thought not to beat him...

your decision is really good. May be he not a thief but the situation can press him to do this.

If you had beaten him, even if he was a theif trespassing on your property, he could sue you and you could be arrested for assault. Sounds unfair that we can't protect our possessions but thats the law. I think you can restrain someone or make a citizens arrest but you risk being attacked that way. Its better to let them go and keep your own life safe.