Is this man interested in my daughter?

I took my 2 boys and daughter to go see Cars 2 over the weekend. We saw the early show so it was semi-empty. I did notice that there was an 80 year old man in the theatre who i saw from the sex offender registry. This is not the first time i saw him in a kids movie. A few months ago I spotted him sitting in the theatre of both Rango and Kung Fu Panda 2. What should i do? He is very creepy looking. Im not sure what he said yesterday to my daughter but he muttered something about buying her some pop corn.