American police use a 0.68 caliber pepper ball gun (also known as pepper spray or pepper gun).Pepper gun (also known as pepper spray or pepper gun) used by American police is a non-lethal weapon, which is used to control and subdue people who do not obey the law or pose a threat.Pepper gun uses a natural compound called "capsaicin" as a stimulant. It will produce a strong pungent smell and irritating smoke, making the target feel difficult to breathe, stinging eyes and coughing violently. Because this weapon will not cause permanent harm, it is regarded as a safe and legal non-lethal weapon in many cases.There are many cases in which American police use pepper guns. In some cities, the police will use pepper guns to disperse protesters or quell other riots. Sometimes, it is also used to control suspects who refuse to follow instructions, especially in cases involving minor crimes or harassment.However, the use of pepper guns has also caused some controversy and criticism. Some people think that pepper gun is just a means of excessive force, which may cause unnecessary pain and harm. In addition, there are some challenges in the supervision and regulation of the use of pepper gun, because this weapon is potentially dangerous and may be abused or misused.