How Did the Killer Pull Off the Killings? (MAJOR SPOILERS)

Over the course of Charade, four men are murdered:

Unnamed bit player -- as Audrey Hepburn's husband: thrown off train.

George Kennedy -- drowned in his hotel room tub.

Ned Glass -- throat slashed when he takes a late night elevator ride

James Coburn -- the most elaborate: tied by ropes to furniture legs so he can't move his hands, then suffocated by a plastic bag over his head.

The killer turns out to be funny guy Walter Matthau -- here playing equal parts serious and jokey as a CIA bureaucrat who turns out to be the former crime partner of the victims. In 1963, Matthau was tall and fit enough to believably play a tough guy..but only so far.

We never see Matthau commit these killings, not even in flashbacks. So it is left to our imagination as to how he did it.

One is easy: Ned Glass -- the oldest and least physical threatening of the victims -- gets his throat slashed in darkness of an elevator with the lights turned out. OK -- I can see how Matthau did that one.

But how did Matthau overcome huge, hulking, hook-handed George Kennedy? I'll guess: Matthau filled the tub with water before Kennedy came in, knocked out Kennedy from behind, dragged him into the tub, held him underwater until he drowned(but what if Kennedy revived? and what about that hook?)

James Coburn's murder required a lot of time and effort, so again I'll guess he was knocked out from behind. Then tied up with the ropes so he couldn't move -- perhaps Coburn was alive to watch Matthau do this; he lives long enough to scratch the name DYLE on the carpet. Then Matthau put the bag over his head.

As to the bit player husband on the train in the opening: could Matthau be sure that throwing the man off the train would be enough to kill him? Let's figure that Matthau shot or stabbed or strangled the victim before throwing him off (his face is bloody from the fall.) And the man was killed while in his pajamas -- Matthau likely surprised him in his train car while he was sleeping.

I GUESS all these murders were "do-able," but Matthau was pitted against some tough hombres here -- and didn't have much time to drown Kennedy.

Its movie magic of a sort -- we don't see the killings so we have to imagine them or simply accept them. And in the earlier part of the movie, we simply can't picture WALTER MATTHAU committing these brutal murders. (His killer certainly has reason: the four victims allowed him to rot in a German POW camp with multiple, painful gunshot wounds during WWII.)

I'll add this: to overpower first George Kennedy and later James Coburn, perhaps Matthau didn't just hit them over the head(so uncertain in effect.) Perhaps he grabbed each man and put a hankerchief with chloroform over the victim's mouth.