The material in this report stems from an Executive Session held in November 2010 for a discussion by law enforcement leaders about their approaches to managing major events. Most chapters conclude with recommendations and lessons learned from the discussions. The format for each chapter consists of specific Session participants' comments on lessons they learned from their agency's policing of various types of major events. The chapter on "Planning for Disasters" provides lessons from hurricane Katrina, the Minneapolis bridge collapse, and the 1999 World Trade Organization conference in Seattle. Chapter 2, "A 'Softer' Approach to Crowd Management: The Vancouver Model," discusses tolerance and police restraint in winning over Olympic crowds, along with the use of discretion and crowd interaction as the key to policing Mardi Gras crowds. Chapter 3, "Policing Sporting Events and Celebratory Crowds," addresses lessons learned from preparing for the seventh game of the National Basketball Association finals, 2012 London Olympics planning, and the Chicago Stanley Cup victory parade. Chapter 4, "A Candid Assessment of the National Incident Management System," addresses the police response to an unplanned event during a planned event; and chapter 5, "Working with Multiple Agencies: Who's in Charge," discusses the coordination of police policies and actions for major events that involve multiple police agencies. Other chapters address the importance of mutual aid in event management for mid-size cities; preparing for protesters at major events; communications, video, and social media as factors in the character and management of major events; post-event litigation; and advice from Federal agencies.