- Author Dennis Lehane joined to talk about his reaction to the Boston Marathon bombing.
- Emily Rooney talked to Jim and Margery about the ongoing investigation.
- Patrick Chagnon, President of Blueline Risk Mitigation Group, talked about making communities safer in the wake of attacks.
- Dr. Michael Zinner of Brigham and Women's Hospital talked about his hospital's emergency efforts.
- Global Post's Charlie Sennott put the Boston bombing in an international context.
- Dan Ariely talked about gun reform and the public's waning interest in passing gun laws.
- The Takeaway's Todd Zwillich joined from Washington D.C.
- Brian McGrory from the Boston Globe talked about trying to identify the bombing suspect.