Math check my answer

A football flew toward Uncle Tommy’s house and shattered his glass window. Three suspects were narrowed down.

 

Andrew: Tommy threw that football, I promise.
Billy: I did not do it.
Tommy: Can someone tell me what is going on here?

 

Two of the children lied. Who was the culprit?

 

Billy was the culprit 

 

andrew is lying 

 

billy is lying

 

tommy is telling the truth