Stark Weapons Assisted Trooper
(TL/DR version: stark gives the mark 2 to the NYPD to test against increasing meta-human, or mutant, criminals)
Tony Stark's coming out as Iron Man was a slap in the face to the countrie's established crime fighters, not only the military. With "super-human" heros came an escalation of super-human criminals. Increasing disparity in the new mutant or "meta-human" population was causing more and more problems for localized police forces.
New York city especially realized this problem. with "district-x" (
http://en.wikipedia.org/wiki/District_X), a ghetto comprised of mutant human inhabitants, police forces had to adapt.
A specially trained unit of policemen were trained by the NYPD to combat criminals that might have super-human abilities, but despite their training there was little they could do against mutants who greatly outpowered them.
After the military's aquisition of the War Machine armor pressure was put onto Stark to release his technology into the hands of the civilian police force. Reluctantly, Stark agreed to allow the NYPD to test several modified "mark 2" style armors for police duty.
These modified armors were called "iron s.w.a.t." These armors are significantly less powerfull than Mr. Stark's Iron Man armors, however the S.W.A.T. armor's ability to increase the wearer's durability, stamina and strength gives the NYPD officer an increadible advantage over normal human beings and puts them at par with most meta-humans...
Because the armor was built with a much weaker arc reactor power source there is no flight capabilities, this also means that the classic iron man "repulsor blast" feature is absent. Despite the increased strength the wearer is still vulnerable and thus is equiped with a tactical shotgun, a hand-gun, a batton and a shield (the shield is as much for the wearer's protection as is to protect the suit, they are after all very expensive).
I can't take all the credit for this idea, I was first introduced to the concept through this piece of artwork on deviant-art:
which was actually an entry in a contest by another member which entailed someone "skining" their blank line-art.... and apparently the idea of a police force specifically trained to fight super heros and mutants is strait out of marvel comics actual storylines...
so... I know that was alot of reading, and I'm sorry, but I thought the backstory was actually interesting enough to deserve a good write up, and of course I had to give credit where credit was due. hopefully you guys like this.