Motive?

Why is the villain even doing anything that he's doing? I get he likes to kill kids, ok, and he hid them in the animatronics, but why does he have them kill the security guards? And he tells his daughter to keep the main dude in the dark after he hires him, don't let him get too close, etc...was he going to kill him even if he didn't find out? Did the last security guard "get too close" to the answers as well? And why even hire security guards if you have these animatronics who kill intruders anyhow?

On another note, did he know that the animatronics would come to life when he put the kids' bodies in them or was that a surprise to him?

Also, when is this supposed to have taken place?