The bombings at the Boston Marathon brought home the challenge law enforcement faces battling smaller and smaller explosives. Trace looks at the detection methods used today, and how new technology will help make us safer in the future.

Read More: "Marines Look for New Ways to Spot Wood and Fertilizer Bombs" "Finding a roadside bomb was never easy, even back when insurgents made their improvised explosive devices (IEDs) from old artillery shells and other metal parts." "T-Ray Tech Spots Bombs, Drugs from a Mile Away" "Scientists have replicated Superman's X-ray vision to see through clothing or packages in order to spot security threats." "How Bomb-sniffing Dogs Work" "When the phone rang one morning in 1972 at Trans World Airlines' New York City headquarters, the caller on the other end delivered a bomb threat." "How can you train honeybees to sniff for bombs?" "Police and military personnel have been using dogs to sniff out explosives for decades."