I quite enjoyed this episode - Troubled Waters - as the title perfectly reflected Danziger's situation. He was a very concerned man, his lover was going to blow the whistle and his rather wealthy wife would slice him and dice him from all her millions! In such a scenario making out he had a heart attack (sympathy from his wife) whilst cunningly creating the perfect alibi (in the sick ward of a ship's ward). So perhaps he was at the "Poppers" - after all Columbo did find the empty capsule in the swimming pool filter. As for the gloves - yes they were a curiosity. I suspect Danzinger did want them to be found - in order to incriminate the main suspect. All those little pieces of evidence were adding up in Columbo's mind towards the musician. However what a perfect end those gloves played... when Columbo took the prints fron the INSIDE of the glove!!! Yes!!!!!

How many killers endangered themselves physically? The only other ones I can name are Paul Galesko and Tommy Brown.