I suspect that you're mistaken on what semi-automatic means. Basically all of the rifles likely to be carried by law enforcement are semi-automatic, except for sharp-shooters, who my carry a single-shot with a floated barrel.
Semi-automatic is not automatic, and has no burst or rapid-fire mechanisms. All semi-automatic rifles shoot one bullet for each pull of the trigger, and in 2015, that's the norm for just about every patrol rifle in the world, except for those needing long-range accuracy, which is a fairly niche application nowadays.
The comment I responded to said that in addition to law enforcement, it's common for soldiers to patrol the streets, too, at times.
If I had to guess, I'd say they would prefer using the weapons they are accustomed to, which are probably not the same that LEO's use. Now I don't know much about the French military, but where I come from, I doubt the military even has appreciable amounts of semi-automatic rifles, as even the military police always use the same assault rifle everybody else does.
Just for clarification's sake, the rifles in question carried by the French army are almost certainly automatic-capable, but like most military organisations around the world, I would expect them to be configured in semi-automatic mode, as you will run through a full clip of ammunition in two short bursts if you're in automatic mode, and that will mostly be a waste of ammunition, unless you find yourself confronted with a massed charge. It would be difficult to believe that they weren't configured in semi-automatic mode in a friendly-territory urban setting!
Ah, my apologies. I read the comment backwards from what it was, so thanks for the clarification.
That said, I have no idea what the French Miliary use. I would guess a lot of H&K stuff. In the U.S. at least, swapping out from an M16 to an AR-15 is pretty natural, but I have no way of knowing what the transition is from or to in France.
Semi-automatic is not automatic, and has no burst or rapid-fire mechanisms. All semi-automatic rifles shoot one bullet for each pull of the trigger, and in 2015, that's the norm for just about every patrol rifle in the world, except for those needing long-range accuracy, which is a fairly niche application nowadays.