History
Christopher Walsh caught a picture of Maria Hill leaving the S.H.I.E.L.D.[1]
He then joined H.A.M.M.E.R. and intercepted an email sent by Tony Stark to Maria Hill.[2]
Christopher M. Walsh later located Stark through the activation of the armor's repulsor battery and immediately reported this to Norman Osborn.[3] When Walsh tried to mislead Osborn, he was caught and arrested by his supervisor.[4]