A more thorough explanation:

Inner-city post-traumatic-stress defense is a self-defense theory that suggests a defendant who uses unreasonable force may be acquitted if they live in a dangerous environment that heightens their fears of injury to life or limb so much that the force used seemed reasonable and necessary to the defendant. This defense is also known as urban-survival syndrome, urban-survival defense, urban-fear syndrome, or urban-psychosis defense.

One example of inner-city post-traumatic-stress defense is a case where a person living in a high-crime area is attacked by an intruder in their home. The person may use excessive force to defend themselves, such as using a weapon, and argue that their fear of harm was so great that the force used was reasonable and necessary.

Another example is a case where a person is confronted by a group of individuals who they believe are going to harm them. The person may use force to defend themselves, even if it seems excessive, and argue that their fear of harm was so great due to their environment that the force used was reasonable and necessary.

These examples illustrate how the inner-city post-traumatic-stress defense can be used in situations where a person's environment has caused them to have a heightened fear of harm. The defense argues that the force used was necessary to protect themselves from harm, even if it may seem excessive to others.