Disabling enemy AI

I'm looking to take some pictures of the Grunts in Halo: Combat Evolved for a possible project. Of course, this isn't easy when they keep running from or shooting at you. Is there a program that will allow you to disable the enemy AI so that they don't do anything?

I suggest using the console command game_speed #, where # is an integer between 0 and 20. 0 will cause the game to pause.

In order to be able to use console commands, you need to enter Developer Mode.
To do so, create a shortcut of the Halo executable, and in the target field of the shortcut add

-console -devmode  

You might have to put the rest of the target between quotations marks, e.g.

"C:\Program Files\Microsoft Games\Halo Custom Edition\haloce.exe" -console -devmode

More information can be found here.

Once the game is started in Dev Mode, the console can be accessed using the ` or ~ key on QWERTY keyboards (² on AZERTY, I believe).