My 3yr old son has recently developed this liking to guns and shooting games. We don't have toy guns at home but he will pretend with his hand and pretend to shoot people. Is it okay?

Instead of prohibiting gun play, you can use this opportunity to teach him on how guns are weapons which can hurt people. Rather than discouraging it, you could get him a rubber dart gun and a bulls eye board for him to practice hand-eye coordination. http://www.pbs.org/parents/raisingboys/aggression05.html http://www.webmd.com/parenting/features/toy-guns-do-they-lead-real-life-violence