Cameras and the checks

This is the full list of what the API gives you. Text in brackets at the end of a note is extra detail you can skip on a first read.

Surveillance cameras and the crime checks

This is the class to start from. Cameras() lists the security cameras, SetCameraActive switches one on or off, and IsPlayerWitnessed and IsTrespassing tell you whether the player can be seen or is on trespassing ground right now.

public static class Surveillance
{
    public static List<SurveillanceCameraInfo> Cameras();
    public static bool IsPlayerWitnessed(bool crime = true);
    public static bool IsTrespassing { get; }
    public static bool SetCameraActive(string id, bool active);
    public static bool IsAvailable { get; }
}

Method	Returns	What it does
`Cameras()`	`List<SurveillanceCameraInfo>`	Every security camera in the scene you are in.
`IsPlayerWitnessed(crime)`	`bool`	`true` when someone could see the player right now.
`SetCameraActive(id, active)`	`bool`	Switches a camera on (`true`) or off (`false`).

Property	Type	What it means
`IsTrespassing`	`bool`	`true` while the player is in a trespassing area, and a moment after.
`IsAvailable`	`bool`	`false` when an event could not be set up.

SurveillanceCameraInfo a snapshot of one camera

Cameras() gives you one of these for each security camera. Pass its Id to SetCameraActive. (It is built from the game’s SurveilanceCamera.)

public sealed class SurveillanceCameraInfo
{
    public string Id { get; }
    public bool Active { get; }
    public float Range { get; }
    public float Fov { get; }
}

Property	Type	What it means
`Id`	`string`	The camera’s id, for `SetCameraActive`.
`Active`	`bool`	`true` when the camera is switched on.
`Range`	`float`	How far the camera sees, in metres.
`Fov`	`float`	How wide the camera sees, in degrees.

Things to know

Cameras() lists every security camera in the scene, even those switched off in the scene. (It includes cameras whose object is inactive. Active is the game’s own active flag, Range is its range field and Fov is its FOV field. The id is the object’s save GUID (see the glossary), or its scene path when it has none.)
SetCameraActive(id, active) switches a camera on or off. The camera’s own signals fire as they do when the game switches it. It returns true when the camera exists, and also when it is already in the state you asked for (nothing is done then). (It calls the game’s SurveilanceCamera.TurnOn or TurnOff, which also set the camera’s Witness component and fire the game’s on and off outputs. It returns false when the camera has no Witness component.)
IsPlayerWitnessed() tells you whether someone could see a crime right now. It is true when at least one person or camera has the player in sight. It does not roll the dice the game rolls for a real sighting, so true means a crime committed now could be seen, not that it will be. By default it skips watchers that do not look for crimes; pass false to count them too. (A witness is an NPC with a field of view or a surveillance camera, the same set the game’s crime checks use. With crime true, witnesses with dontDetectCrimes are skipped. The game’s own check (Witness.IsWitnessed) rolls propability, 0.5 by default. A camera counts when it is active and its own per-frame check had the player in view in the last frame. The call does not start the game’s NPC detection cooldown, fire a camera’s outputs or start its alarm timer, and it does not raise PlayerSpotted or Law.Spotted. Because it ignores the cooldown, it reports a witness that the game’s own check would still skip for a moment after a detection.)
IsPlayerWitnessed is slow, so do not call it every frame. Call it at most a few times a second and keep the answer. (Each call runs FindObjectsByType over every witness and one raycast for each NPC witness that has the player inside its range and view angle.)
IsTrespassing is true while the player is in a trespassing area, and a moment after. It stays true for about one second after the player leaves, so it can still be true right after TrespassLeft. An area that is turned off for this player, such as the other sex’s bathroom, never counts. (It reads the game’s trespassing flag on each TrespassingArea, which the game clears after a one second cooldown.)

Limits

IsPlayerWitnessed() gives false with no save loaded.
SetCameraActive returns false for an unknown, empty or null id (an empty or null id is also written to the log once), for a camera that has no way to see the player, and while a save is loading or saving.