|Cause of death||Single gunshot wound|
|Children||Christina Marx (daughter)|
|Other family||Eric Marx (son-in-law)|
|Appearances||"The Double Down"|
|Portrayed by||Unknown male actor|
Frank Anderson is a murder victim that Ryan and Esposito are assigned to investigate in "The Double Down".
Frank was killed by Jason Cosway, cause of death being a single gunshot wound to the midsection in the back. Cosway staged the incident to look like a mugging gone wrong. Frank was the father of Christina Marx, whose husband Eric 'traded murders' with Cosway, killing Cosway's wife Ashley whilst the other man established a rock-solid alibi.
Eric wanted Frank's rent-controlled apartment, which would stay that way if the lease was taken over by a family member, i.e. his wife. He had also borrowed money from his father-in-law, which Frank was pressuring him to pay back.