The Decembrist (No. 12) - S2-E8
Revealing mistake: When turning the guy with C4 around his neck, the 4 person safe box window shakes briefly. If this was a bomb proof safe box, the glass would be at least 1.5"+ in thickness and would not shake simply from some walking. That box would be shrapnel to a C4 bomb inside. (00:26:30)
Answer: The man Red killed, Sam Scott, was Lizzie's adoptive father, not her biological one. However, at that time Lizzie (and thus the audience), was led to believe her real father abandoned her and her mother, so expect more secrets to be revealed how her real father actually died (or if he's even actually dead).
Bishop73