Were soldiers shot on the spot for cowardice in World War 1?

I'm sure this happened dozens, or more likely hundreds of times, if one considers every army on every front. It may have been more common in the armies of nations where ruthless discipline was more usual, such as the Russian, Ottoman, and German. George S. Patton, Jr., who is far better known for what he did in WWII, was head of the tiny, infant American Tank Corps during WWI, with the rank of Lieutenant Colonel. He said he killed an American soldier on the spot for cowardice, and he might have. Any knowledge we have of such incidents comes to us as an anecdotal account - something someone said they saw, or did. In armies where the practice was acceptable and perhaps occurred with some frequency there likely would have been no official reporting of it, and the brass would have wanted knowledge of such events to spread no farther than among the other rank and file soldiers, so that they could know what to expect and fear if they too misbehaved. (You don't want the folks back home to know that officers of their own army are killing their own people, or that an officer killed your son). In most armies the usual practice is to very publicly prefer formal charges, convene a court martial, give the accused a fair trial, and THEN execute them, for the same reason: "To encourage the others". This was what was done on a wholesale scale when the French Army mutinied in 1917, but I'm sure some of the more mouthy ringleaders never lived long enough to get their court martial.