If you're shooting someone, that means you have reason to resort to lethal force. You need as much put-down as possible. This is literally one of the most useless inventions I've ever seen.

An even better idea would be for the cop to ask the alleged offender to go to a 'time out' while the cop contacted his legal representative for written authorization to shoot.

Am I the only one that thinks police should be skilled enough with such a deadly weapon to hit a persons leg?

Sure if they have a ranged weapon then you gotta take them down as quick as possible but there are plenty of people that can hit a small moving target at a fairly large distance, police officers are paid professionals and I believe they should be capable of doing so or have their firearm taken away.

I don't know about shouting "LESS LETHAL" before firing. Pretty sure you want the fear of death at the top of the criminal's mind when staring down the barrel of a firearm.

Doesn't this transform a gun into a flashball ?
Also, while we have proofs that non-letal weapon like pepperspray or tonfa are very often ineffective against agressive and/or determined person and while we have several reports of people still able to move an fight after being shot several times and even with multiple lethal wounds, do we really need less lethal guns ?

Nice idea but in fact it is a bullet-trap grenade , something that has existed since WWI. The application for pistol in a non lethal version is nonetheless interessant in particular because the police officer does not need another non-lethal side-arm. It would even be better if there was no carrier to be added as is usually the case with bullet trap grenade because the rifle has a specific end around which the grenade can go.

Just another decision the police would have to make in a tense situation. Another problem would be the possibility of the gun not properly loading the next round because the plastic add-on had slowed the slides movement.

First of all regarding wounding as a method stopping an assailant.....waste of time. If you have a gun and your opponent is also armed you need a lethal shot first, wounds unless in a vital spot do not always incapacitate every time, the shock of impact can nullify pain for up to 12 minutes.....not necessarily incapacitate....if you pull a gun on a law officer, expect to die.

Furthermore has no-one heard of a taser? For those less than lethal situations.....

+1 for Tasers. This invention is not sane. For one, the concept of less lethal with ballistics assumes that firearms are lethal in the first place; the evidence says that for service handguns, at least on a single shot, rarely and certainly not instantly. Tier 1 SF might neatly double tap a tango in the head, but that is because they drill with hundreds of rounds a month. The rest of us will be counting ourselves lucky to hit a moving target whilst under stress. So where will that ball end up? Probably nowhere that will incapacitate a determined (or doped up) would-be assailant. Which brings me to the second point - under stress, with a semi-auto or revolver, most people will fire at least twice. They will look for their rounds to take effect, and, unlike the movies, targets don't always reel backwards on the impact of a round. So, with the less lethal round expended, one, or very likely, more lethal rounds will follow before the perpetrator behaves in a manner the shooter expects. With a taser, if it makes contact and activates (neither is guaranteed) the perpetrator goes down.