So, I may jump around here a bit, but just bear with me.

I know a lot of you know that I am too scared to play the games. But, I have watched every Markiplier video on the game, including most of the re-hashes. I have also read quite a bit of theories, and watched numerous videos. So, that is where I will be getting my evidence from.  

I think Golden Freddy was the suit used to kill the children. However, Purple Guy is Spring Trap. And Spring Trap is phone guy.

Explanation: 
- If you put the games in time line order, it goes FNAF 2, FNAF 1, FNAF 3, which is something everybody can agree on. 
- Golden Freddy's suit looks really deteriorated; more so than the normal suits in the first game ( 2nd in the time line ) ,and the toy suits in the 2nd game ( first in the time line ). This leads me to believe that Golden Freddy is the first original suit that was used at the Diner.
- Golden Freddy is slouched over, like there's no exoskeleton in it. That would support my theory that the Golden Freddy Suit was used to the kill the kid that was put into the Marionette, as shown in the mini games in the 3rd game. 
- You see Golden Freddy in the 2nd game in story order, but not the first.
( This theory I am not 100 % sure about, but I am using what knowledge I have to make reasoning of it, so don't attack me for this one ) 


So now that I have established my reasoning for believing that the Purple Guy ( who everybody knows is the killer of the kids ) used the Golden Freddy Suit to kill the first kid, I will explain why Phone Guy is the Purple Guy, who is Springtrap. 

- The Purple Guy has a gold badge in one of the mini games. It is rarer to see, but it does happen. This leads me to believe that Purple Guy is a guard of some sort. Perhaps some kind of security guard... ? 
- Purple Guy is holding something in one of his hands. While it is 8 bit Atari like graphics, a lot of people believe that he is holding a phone. 
- Purple Guy is said to be an employee that was never caught ( putting multiple things into one here ) , which would explain how Phone Guy has been working for Freddy's for so long, as he says as much. 
Put those first 2 damning pieces of evidence together, the Purple Guy is holding a phone and wearing a badge, and it leads me to believe that Purple Guy is Phone Guy. 



Now that I have explained why I think Purple Guy is Phone Guy, I need to explain why Purple Guy is Spring Trap. 
This is one is only half way simple to explain. 
 
- If you played ( or watched, as is my case ) the mini games in Five Night's At Freddy's 3, you will see Purple Guy get chased into what appears to be Springtrap. Then he dies. 
- Phone Guy dies in the first game, which is the 2nd in the story. He dies on the 4th night... on the 5th night, it is noticeably harder. That could be because the Anamatronics know that Phone Guy is dead because they put him into Springtrap, so now all they have do is take care of you. 
- Springtrap is only in the 3rd game, the latest in the series. He is never mentioned, or even thought of in the first two games. That's because Springtrap is still alive, and is Phone Guy. 

So why doesn't Springtrap appear on the 5th night in FNAF 1, then? Because he has just died, and it not ready to be a living anamatronic yet. I believe that children who are believed to have been stuffed into the Foxy, Freddy, Chica, and Bonnie suits had to wait awhile to get used to their new bodies before they could move around. 




Thanks for reading this, and if you have any questions on it, or why I think what I think about something, then feel free to ask. If you need me to explain something further, they just ask, and I will try to do the best that I can. I believe I have an advantage in explaining things, as I have never played the games, so I be unbiased when it comes to theorizing on certain things. 

I disagree. If Spring Trap was indeed Phone Guy, then how come there are Phone Dude and a new Phone guy in Fnaf 3? Also, Spring Trap does appear in the second game. Remember the Paper Plate dolls? Go to the camera where you see a Paper Plate Doll of Balloon Boy. There are 3 paper plates, and the middle one is Spring Trap. I don't think Golden Freddy was the suit to kill the children, as it only has four fingers, while Spring Trap has five.

I do know that Purple Guy has a golden badge, but it doesn't mean that he used to be an employee at Freddy Fazbear's Pizza. He may have been a police officer, and was carrying a knife.

If you look at the white poster on the first game (Forgot which camera), they haven't mentioned that the killer was an employee. As for Phone Guy who died in Fnaf 1, he was pretty much likely stuffed into a Chica suit.