If you had asked these questions a few years ago, shaman, I probably would have been able to get you some pretty solid answers but unfortunately my wife's step-brother has since passed away.
He spent his entire career in law enforcement CSI with fingerprint analysis being as his specialty.
One interesting multiple murder case his department was instrumental in positively identifying which resulted in a conviction there were no fingerprints at all. The only hard evidence they had was a partial palm print he termed a "writers print" on a hand written note which they were able to match to the prime suspect's palm.
