With all this technology and heritage behind it, FN realized there was a hole in its law enforcement product line. It needed a shotgun.
The police shotgun is a tried-and-true tool, even in today's increasingly high-tech police arsenal. There are times when stun guns, OC spray, and verbal compliance techniques fall short and a reliable load of "00" buck is called for.
At that moment, the delivery system is vital and has to be the most reliable possible. Over the past 75 years or so, the pump shotgun has proven, and re-proven, itself in the field. Dirt, snow, rain, filth, neglect, and worse are no stranger to the police shotgun and the pump action has established its credentials solidly.
When a really nasty job needs to be done, cops reach for their pump shotguns. Historically, that shotgun has been the Remington 870 and/or the Ithaca in various guises. With the introduction of Mossberg, there was a third contender. These days, Winchester also markets a police or "Defender" shotgun.
Basically mirroring one another, these various manufacturers all offer slight differences in features, but all are basic, pump-action shotguns, and the choice is more subjective than factual.