here is abc s alex perez with more. reporter: along with fireworks, the sound of gunfire filled the air in parts of chicago this holiday weekend. the biggest surge in gun violence the windy city has seen all year. among the dead, tanya gund killed while barbecuing in a park with her daughter and loved ones late sunday night. her panicked family frantically calling 911. and then the ambulance came and they took her. and they shot her in front of the daughter. reporter: the city s top cop blaming part of the problem on gun laws. there s a greater sanction for the gang member to lose their firearm from their gang than there is to go to jail for possession of that gun. reporter: mccarthy says police confiscated more than 100 guns over the weekend. but in our special abc news chicago violence summit with diane sawyer we met several