"Please put down your weapon. You have twenty seconds to comply."―ED-209 to Kinney.
The Enforcement Droid, Series 209, or ED-209, were a fully-automated series of peacekeeping machines created by Omni Consumer Products. The units were programmed for urban pacification, but OCP also negotiated contracts with the military for use in war.
The Future of Law Enforcement
"It gives me great pleasure to introduce you to the future of law enforcement: ED-209!"―Dick Jones[src]
During its first demonstration, ED-209 malfunctioned disastrously, blasting junior executive Mr. Kinney to death over a sustained period of time. Unable to stop the droid's rampage, Dr. McNamara and his fellow technicians struggled to gain control over ED-209, having to pull some sort of plug to finally shut it down. Because of the Kinney tragedy, the RoboCop program was given the green-light.
When RoboCop attempted to arrest Dick Jones (who was the collaborator of notorious cop-killer Clarence Boddicker), Jones deployed ED-209. ED-209 blasted RoboCop with his automatic cannons, then smacked RoboCop across the room with a blow from its left arm. ED-209 then attempted to shoot RoboCop in his damaged visor, but RoboCop forced its blasting left arm into its right, destroying it and causing ED-209 to shudder violently from the blow. RoboCop then tried to escape on a flight of stairs while ED-209 followed. When ED-209 got to the steps, however, it was stumped. The robot's huge feet couldn't support it on the small steps and it fell on its back, unable to get back up because of its digitigrade legs. RoboCop took the opportunity to escape.
After its scuffle with RoboCop, Dick Jones took the opportunity to give the ED-209 project the green light, what with RoboCop seemingly gone. He fixed ED-209's damaged arm and posted it at the entrance of OCP. ED-209 eventually spotted RoboCop, who had reaffirmed his identity as his original self, Alex Murphy. He had stolen a Cobra Cannon from Clarence Boddicker (whom he'd just killed) and used it to destroy ED-209, who was demanding that he move his car.
Attorney General Marcos later approved the 209 series for deployment in five American cities, including Detroit. Despite widespread complaints of malfunction, the 209 series continually stayed in service even when OCP was taken over by the Kanemitsu Corporation. They were rarely seen on the streets and usually used as guards near OCP buildings.
The ED-209 was armed with three automatic cannons, two on the left platform, one on the right platform with an auto-shotgun and a rocket launcher capable of firing three rockets. It also had additional combat programming, enabling it to melee attack at closer ranges. Its speech center could synthesize human voices for peacekeeping matters, or animal-like sounds when injured or angry.
Despite its size and power, the ED-209's logic circuits were its weak-point. It could not process information as quickly as a human brain and could not manuever flights of stairs.
ED-209 also suffered from a manual override weakness that allowed an unarmed and sufficiently skilled hacker to access its command system and take control of the droid. Nikko managed to achieve this by opening a compartment on the droids right leg which revealed three serial ports. She manually bypassed these ports and with her laptop was able to access the ED-209 command system interface. From there, she was able to issue commands directly, thereby taking full control of the droid.
An ED-209 appears in Mortal Kombat 11 as part of one of RoboCop's fatalities, shooting his opponent with its machine guns.
Behind the scenes
The production team explains in the Criterion Collection featurettes that their approach to designing ED-209 was that OCP basically applied the same principles they used for modern automobile contracts to a military-grade walker-drone: OCP designed it to look impressive and flashy, but it really isn't very reliable "under the hood". Like a modern American car cranked out by vacuous corporate executives and lowest-bid design teams, they cut corners everywhere. Punctuating this, Dick Jones even outright states that it was irrelevant if ED-209 actually worked: it only had to outwardly look just impressive enough that it could dupe the rest of the board and potential buyers into accepting the development contract. It's the Ford Pinto of robot walker-drones. Some of the design features on ED-209 are supposed to accentuate the "style over substance" comparison to corporate-designed low-bid automobiles, such as how it has metal grating around the front of the head like some modern SUV's - which apparently is only there to look "cool", and has no real function.
Highlighting that Jones cares more about contracts than how products are actually used, from a purely physical standpoint the ED-209 is ill-suited to urban pacification and police work: it has difficulty simply climbing stairs. The entire point of the ED-209 project was just as a backdoor to an even more lucrative military contract, and deploying them for police work was just a badly conceived test run. It was the equivalent of selling Abrams tanks or Apache helicopter gunships to Detroit, marketed as an actual replacement for patrols by mobile beat-cops and SWAT teams. This doesn't even begin to cover the severe programming shortfalls in the ED-209: even on a military battlefield, they'd probably end up shooting at units on their own side.
The irony of course is that Dick Jones ended up being hoisted by his own petard: he intentionally developed ED-209 as a cheap inferior product to sell like snake-oil to unsuspecting buyers, but then honestly thought he could rely on his flawed creation as his ace-in-the-hole against RoboCop.
In a twist of hilarious irony, at the beginning of the sequel, the defective ED-209 is approved for widespread use anyway. In many ways like the Bradley vehicle. Making Dick Jones offense at being sidestepped, superfluous.
The propsmasters in the Criterion Collection featurettes point out that they cheated during RoboCop's fight with ED-209 in Dick Jones office: it is obvious even by looking at the prop that the weapons-stub arms cannot be turned to shoot sideways, and thus, it was actually physically impossible for RoboCop push one of its arms to shoot off the other arm. He might have been able to do this if the other arm was partially damaged and hanging by wires, but in the next scene ED-209's remaining arm is still firmly attached.