The first and most important defensive countermeasure in keeping yourself and loved ones safe, is awareness. By constantly educating yourself to what dangers you could potentially face, you become better prepared to recognize these dangers and react appropriately.
Each of these links provide information on real life scenarios and how you can better prepare yourself to ensure your safety. Having the knowledge and a preplanned set of actions to take for as many scenarios of danger you could face, can greatly improve your chances of not being victimized.
First and foremost, the key to safety is to continue to learn as much as possible about what dangers you could potentially face, as well as how predators operate.