Source: Investigators found circuit board believed used to trigger marathon bombs. #Bostonmarathon
— Shelley Murphy (@shelleymurph) April 16, 2013
According to Shelley Murphy of The Boston Globe, a circuit board was used to trigger the explosions at the Boston Marathon yesterday and was found by officials. 3 people were killed, including Martin Richard — an 8-year-old — and Krystle Campbell, a 29 year old who was from Arlington, Massachusetts.
In addition, one of the bombs was placed across the street from where Governor Patrick was sitting earlier in the race.
More additional information was provided by ABC. According to them, the circuit board was a piece of one bomb.