A response to a threat or an actual attack is full of questions. State laws dictate what is a proper response. I have used several tactical flashlights in my neighborhood at night. In every case the threatening person backed off and beat feet. At 70 I don't have to run or stand and take a beating. My next line of defense is a large canister of high-strength pepper spray in a stream form. I had one 16 year old neighborhood boy get nasty one night when he came home drunk. All I did was pull out the pepper spray and point it at him. He had a previous encounter where a police officer had sprayed him. The last resort would be the .380 Colt.
The trouble is that if the mugger, thief, etc. is smart and determined they will set it up that you don't have time to respond. Around here they simply walk as close as they can and give you a hard punch to the head to incapacitate you.
The best defense is to constantly look all around you and learn to judge where and when you might be in danger and avoid a situation where the possible assailant could surprise you. If you are alert to your surroundings the thugs generally think twice before any attack. They are looking for victims that are somewhat oblivious to their surroundings.
Sometimes the inner cities are Darwinism at its most basic level.