Rose Wynters said this quote

And for God's sake, if you need to shoot make sure to release the safety ,” he murmured, as we moved across the front, careful to stick to the shadows as often as we could. So far, I hadn't seen anyone, not even zombies. It wasn't uncommon for a straggler to come along, every now and then. Lucky for us, we were remote enough that we hadn't had any major issues with any hordes locating us. The men were quick to dispatch any zombies that hung around, not willing to take the risk that somehow they could communicate with each other. Not to mention, the zombies were strong and fast. It was better to end them, rather than to risk them one day killing one of us.