Pepper Spray, technically called "oleoresin capsicum," is a controversial chemical weapon in the arsenal of law enforcement. Originally developed as a bear repellent, the substance was certified for police use in California in 1992. When released, it causes intense pain, coughing, gagging, shortness of breath, and burning of the eyes and skin. It immediately inflames throat, nose and lung membranes and induces copious secretion of mucous in the lungs, nose and mouth. The pain caused by the spray is so intense that, once sprayed, many people temporarily lose the ability to stand. Pepper spray in combination with pre-existing respiratory conditions such as asthma can be fatal.

The immediate damaging effect of a gunshot wound is typically severe bleeding, and with it the potential for hypovolemic shock, a condition characterized by inadequate delivery of oxygen to vital organs. In the case of traumatic hypovolemic shock, this failure of adequate oxygen delivery is due to blood loss, as blood is the means of delivering oxygen to the body's constituent parts. Devastating effects can result when a bullet strikes a vital organ such as the heart or lungs, or damages a component of the central nervous system such as the spine or brain. Common causes of death following gunshot injury include exsanguination, hypoxia caused by pneumothorax, catastrophic injury to the heart and larger blood vessels, and damage to the brain or central nervous system. Additionally, gunshot wounds typically involve a large degree of nearby tissue disruption and destruction due to the physical effects of the projectile. Non-fatal gunshot wounds can result in serious disability.

Gunshot injuries can vary widely from case to case since the location of the injury can be in any part of the body, with wide variations in entry point. Also, the path and possible fragmentation of the bullet within the body is unpredictable. The study of the dynamics of bullets in gunshot injuries is called terminal ballistics.

Non-fatal gunshot wounds frequently have severe and long-lasting effects, even after the victim has made a successful recovery. Typically, the consequences involve some form of major disfigurement and/or permanent disability. As a rule, all gunshot wounds are considered medical emergencies that require immediate hospital treatment. Hospitals are generally required to report all gunshot wounds to police.

https://en.wikipedia.org/wiki/Ballistic_trauma

The last 25 years of modern wound ballistic research has demonstrated yet again what historical reports have always indicated, that there are only two valid methods of incapacitation: one based on psychological factors and the other physiological damage. People are often rapidly psychologically incapacitated by minor wounds that are not immediately physiologically incapacitating. Psychological factors are also the reason people can receive severe, even non-survivable wounds and continue functioning for short periods of time. Up to fifty percent of those individuals rapidly incapacitated by bullet wounds are probably incapacitated for psychological rather than physiological reasons. Psychological incapacitation is an extremely erratic, highly variable, and completely unpredictable human response, independent of any inherent characteristics of a particular projectile.