The fantasy worlds of early 20th Century science fiction writers, in many ways, appear to be "now-ish" in terms of the technologies we'll wage war or police the civil population. Many of the weapons proposed a century ago were nuclear-based... well, perhaps "Atomic" was the more appropriate label at the time. Some authors pursued electric guns or "lightening" throwers, and by the mid-20th century the more common man-portable weapon systems were based upon high-powered laser systems.
When I think of new weapon systems... man-portable... and likely to be developed and employed within the coming quarter century, I think that many of the systems will integrate automatic target acquisition processes and coherent light - for"less lethal" confrontations. The term "less lethal" is of course relative and doesn't exclude weapon systems that are proficient at maiming and causing great pain or suffering.
One such system that, given current technological advances, lies within the finger tips of today's weapon designers could encompass the use of high intensity light, automated facial feature recognition, and "high-powered" laser light - and have a higher degree of target incapacitation than current personal small-arms have today.
A single trigger pull would bath the target with the main light function (which may temporarily disorient them anyway), but during that trigger pull the automated eye acquisition, eye targeting, and laser firing would happen in a fraction of a second (faster than a bullet could traverse the distance between shooter and target). I guess after the laser has successfully acquired the eyes and fired, the main light function would end... like a half-second burst of white light. To an external observer, the weapon user appeared to just fire a burst of white light at the head or torso of the target.
Obviously there are a lot of nuances to a "future" weapon like this. For example, would the target blink or close their eyes if the initial "white light" was directed at them? - At night, the answer is likely yes, however the facial recognition systems would still work and even a current "off-the-shelf" laser of the 5-20W range is strong enough to "burn through" the eyelids and damage the eyes. During the day it would obviously be easier... in fact perhaps the "white light" component is not required... instead the shooter merely targets the "head" and the rest of the system figures out the eyes and fires (or fries) the eyes of the target.
There are of course questions about ethics. But, compared to several ounces of hollow-point lead flying at several times the speed of sound, the option of permanent blindness is still a recoverable situation for the target.
[Wandering thoughts in SciFi]