Can a non Jewish baby boy be circumcised by a mohel?

My mum is Jewish and my dad is Catholic. On my dad's side my cousin Catholic and her husband Catholic are finally expecting a baby boy (after 4 daughters!). I'm not going to get into an argument here about whether or not to circumcize. I'm against it, but they want to do it. They don't want it done in hospital b/c they don't like the apparatus used. They want to know if they can have a mohel do it in a temple even though they are Catholic?