With police presence, Rockstar have forever been trying to get the right balance between freedom and causality, leading to everything from forever-aware cruisers slapping you with wanted levels even if the cop itself accidentally clipped you, to escaping vision cones and not knowing exactly what they can and can't see. You have to assume the way the cops activate in GTA V is the most logical solution to preventing the game devolving into Mass Murder Simulator: Serrated Knife Edition, but at the same time this is GTA - either have a police presence that realistically feels like they belong in the city, or let us go hog-wild with a chainsaw. At the end of the day you want to know if your actions are going to cause an unwanted star - as there's nothing worse than having to 'Lose the Cops!' right before you're about to hit a final checkpoint when something out your control activates the all-seeing eye. Tie this into how much influence you have in the city, meaning cops will leave you alone depending on if you're a major player, then factor in Saints Row's idea of calling in a favour to stop an alert and it'd be perfect.
