No they didn't. They didn't cooperate then, ESPECIALLY under the circumstances when they should have been the MOST eager and willing and WANTING to find the person/s responsible for the death of their little sparkplug<quoted text>
Take your own advice.
No they didn't.
They didn't cooperate years later and now almost 20 years later, they still refuse to cooperate. John and Burke have "gone on with their lives" and sadly, to the exclusion of something so very important that also was a part of their lives.
They just don't care. They got away with a crime and are quite content to let it stay cold. Anyone who interprets this any other way is deluding themselves