Is this real or someone posing as a cop? Plus, they tried to add me to their chat list. Very worried!?

"This is captain robert haines with the Gretna, Louisiana Police, computer crimes. We've traced your ip address and are following it because you've exposed to 2 minors. The ladies here are 15 year old volunteers who help us...which means you might be going to jail for a felony sex offense. Lets chat. DO NOT LOG OFF THE CAM OR YOU WILL GO TO JAIL."