2) What can be done to find her killer?
BLUE OWL. Random. 5 cards.
To me the killer is close to home or perhaps this is about starting close to home first. As in the same location as the murder, so I tend to think Baltimore or surrounding areas. As it is the USA - it is safe to say that it is unlikely the killer is abroad if still alive. S/he may have moved further since the murder, but to find him/her it has to start at the location Cisnek was in in 1969. So, her apartment, the shopping center, the car parks, and dumping site etc. Could have been someone within her own circle.
I feel this is saying the killer would have been living in that proximity at the time. Not sure how big Baltimore is, but either near her or within the area for sure. Likely the same suburb or nearby ones. So, not likely two hours away, but closer.
Might be hard to find him/her, but the person may have had addictions and would have been in trouble and caused trouble and not minor issues either. So, perhaps someone that was a criminal or criminally inclined, in trouble with the law yet hard to catch, or a "smoke and mirrors" type.
This person was "known" and unlikely a "secret" at all.