The chairman and CEO of Dick's Sporting Goods announced Wednesday morning that the chain will no longer sell assault-style rifles and high capacity magazines.In an open letter, Ed Stack said the nation's largest sporting goods retailer will stop selling certain weapons, and will not sell firearms to anyone under age 21."We looked at what happened down in Parkland and we were so disturbed and saddened by what happened, we felt we needed to do something," Stack said in an interview on 'Good Morning America .' "So we've decided not to sell these assault weapons any longer in any of our stores."The new measures go into effect today. Aside from Dick's, the Pittsburgh-based, publicly traded company also operates stores under the Gold Galaxy, Field & Stream, True Runner and Chelsea Collective banners.Dick's announced a temporary suspension of assault-style rifles from its stores after the 2012 shooting at Sandy Hook Elementary School in Newtown, Conn., that killed 26 elementary school students and educators.Assault-style rifles were later sold in the company's Field & Stream stores, according to Stack."We're taking these guns out of all of our stores permanently," Stack announced.The gun debate has taken center stage in the wake of the Feb. 14 massacre at Stoneman Douglas High School in Parkland, Florida. A gunman armed with an AR-15 style semi-automatic rifle and multiple magazines killed 17 people and wounded 14 others.-----