Zombies can appear in numerous stages of decay. Some may appear with their flesh completely decomposed, leaving what only appears to be a walking skeleton. Newly infected zombies can often appear to be lifelike as opposed to appearing to be the walking corpses that they are.
This can become tricky when setting out to kill what you believe to be a zombie. There have been several documented cases where people have been charged with murder for killing a newly infected zombie. Sadly, the law does not always investigate zombie terminations effectively and assume the demise was not caused by Solanum, but at the hands of the innocent hunter.
Likewise, many novices make the mistake of killing a living person who they mistook for a zombie. For instance, I was in Wal-Mart just a few weeks ago when I encountered what I thought was surely a zombie. He was meandering around aimlessly, groaning. I went to the sport good section to fetch a machete in order to behead the monster. Just as I was about to strike and decapitate the poor fellow, a rather fat woman walked up to the man and they began to have a conversation. I knew then that the man wasn’t a zombie because the living dead do not talk. It was a close call.
Resource: The Zombie Survival Guide