I think I know who posted the following. It is, I believe, someone whom I respect, so I looked up his list which I've annotated [-].

There are some very good reasons not to have a death penalty in Canada. Those reasons are Brandley, Clarence Lee[RELEASED]; Chew Wing, George[EXECUTED 1937]; Cirofici, Frank[EXECUTED 1914]; Cruz, Rolando[PARDONED]; Ford Heights Four[PARDONED]; Grzechowiak, Stephen[EXECUTED 1930]; Johnston, Dale[FREED]; Marshall, Donald Jr.[FREED]; Milgaard, David[FREED]; Morin, Guy Paul[FREED]; Nepoose, Willie[NOT A CAPITAL CASE-FREED]; Peek, Anthony Ray[RELEASED]. All were convicted wrongfully.

From this list we see that three folks were executed, probably wrongly. All of them were put to death before WWII. It should not have happened.

Nepoose, was not convicted of a capital crime and so was not subject to the death penalty. His second degree murder conviction was overturned.

The remaining enumerated persons were subsequently found to be wrongly convicted either by evidence or technicality; they were released and compensated for their wrongful convictions, not to say that money heals the wrong done them. All of those cases are from the latter quarter of the last century until more recently.

I would say, based on Guest,#'s list, that the ultimate protection of wrongful execution is now quite, good...perhaps even excellent.