When creating incident classifications at Settings > List IR Types, we've added an option where you can set whether images are required for this particular incident type/classification.

If an officer creates an IR and tries to save it without adding images, they will see a popup reminder asking them to add images if images required is set to yes. Your officers will still be able to save the IR but this gentle reminder will help prevent IR's being saved without images attached. You can also toggle the setting from the list of IR classifications shown below: