Range positioning in DECORATE

Which is the property that allows to control how an actor positions before shooting the player? For example, I want a shotgun enemy to shoot from close range and a similar enemy with a sniper shooting from long range. Pretty much like the scripted marine does, only there seem to be hardcoded missile states for those actors. To customize the shooting I would use the A_CustomBulletAttack, but how do I get the monster to engage the player and not roam around waiting there's a chance to shoot? I know I sound clueless but I'm really not very good at programming.

You could use both the +MISSILEMORE and +MISSILEEVENMORE actor flags, if the monsters are more likely to fire they'll be less likely to roam around.

Good one, I didn't know about those flags.