Officer on Ice (designated Case File 1231-1) was an event that occurred during the New Year's Eve incident, where a Police officer was literally put on ice by an arms dealer aligned with Penguin via the use of GothCorp-manufactured cryogenic weapons stolen by Mr. Freeze and supplied to them.
Before Cold, Cold Heart Incident
At some point after the former GothCorp cryogenicist Victor Fries was mutated in a lab accident to become Mr. Freeze, he stole some Cryogenic weaponry that had been illegally developed by GothCorp at the behest of its CEO, Ferris Boyle. He then supplied the weaponry to the criminal gang led by Oswald Chesterton Cobblepot, aka the Penguin, in exchange for their help in trying to help him abduct his former employer, promising to give them access to the weapons (keeping his desire to rescue his wife from Boyle's clutches to himself).
As a result, one of Penguin's arms dealers, Rusty, proceeded to start a sale on the weapons. However, he was caught by a Police Officer who stumbled upon him with the weapon and presumably several other members of Penguin's gang. He was then forced to freeze the officer, with it slowly putting the guard into cryostasis and left the area to make it to a sale, presumably also leaving the rest of Penguin's gang to guard them in the event that Batman showed up. Unbeknownst to him, however, his cryogun also started leaking.
Cold, Cold Heart Incident
Batman, who was in pursuit of Mr. Freeze due to his abduction of Ferris Boyle during a party at Wayne Manor, decided to track down Rusty at South Gotham to find Freeze's destination after interrogating one of the criminals left at Wayne Manor. He eventually found a frozen cop at one of the docks of the Diamond District with several of Penguin's thugs guarding him nearby. After subduing Penguin's thugs, Batman then set up a crime scene, since he needed to find clues to locate Rusty. However, as he lacked the XE suit or its thermal gloves due to it still being under development, he was forced to put off saving the frozen cop. He then scanned the cop and learned the cop was exposed to a substance that was slowly putting him into cryogenic stasis. Further analysis of the compound also had him realize that the cop stumbled upon the dealer, who promptly froze him easily due to the cop not being well-equipped to deal with the weaponry, as well as learned that the gun was leaking. He then decided to use the trail to find Rusty. He then contacted Alfred to notify him about how Penguin's gang is using cryogenic weaponry to attack innocents and put them in ice, requesting that he complete the XE suit if he is to save them. Alfred agrees to work on it in an instant, and asks for the weapon's origin, with Batman stating before signing off that he'll only find out after he finds Rusty and makes him talk. He follows the trail, even foiling a robbery caused by Penguin's thugs involving cryogenic weaponry that somehow caused the building they were raiding to catch on fire, he eventually located Rusty and, after interrupting his sale, proceeded to interrogate him on Freeze's location. Rusty then revealed that Freeze made a deal with Penguin that he'll supply the latter with cryogenic weapons if they abduct Boyle, and were on their way to GothCorp. Batman, realizing what he's implying, accuses Rusty of lying as GothCorp doesn't work on weapons development, let alone cryogenic weaponry. However, Rusty insisted that was where they were headed, and even offered the entry codes to the building as proof. Batman then takes the codes before knocking him out, although he was disturbed at this revelation.
Batman: Finding Penguin's dealer is the key to finding Freeze. I should scan the area for clues that might tell me where he went. I'll come back to help this person once I have my Thermal Gloves.
Chemical Evidence analysis of Police Officer 1
Batman: Whatever this substance is, it's slowly shutting his systems down - putting him into cryostasis. I won't be able to safely remove him from the ice without the Thermal Gloves from the XE suit.
Chemical Evidence analysis of Police Officer 2
Batman: The officer just chanced upon Penguin's men. He wasn't equipped to deal with this cryotech. But the cryogun was leaking.
Scan of residue from leaking cryogun
Batman: If I hurry, this trail will lead me straight to Penguin's men. Then I can make them tell me where this tech came from.
Batman: Alfred. Penguin's men are using cryogenic weapons to encase innocent people in ice. I'm going to need the Thermal Gloves in the XE Suit to break them free.
Alfred: I'll get to work immediately, Sir. Any idea where these weapons are coming from?
Batman: I'll get that answer when I catch up with Penguin's dealer.
Rusty: It's like any other gun, cept instead a'killin' a guy, you're gonna freeze'em solid.
Criminal: How does it work?
Rusty: Just point and click.
Criminal: No, I mean - how does it make ice?
Rusty: I look like a damn scientist to you?
Criminal: I dunno. I'm just askin'.
Rusty: Quit askin' and just listen. Just be careful about what you shoot at, alright?
Batman arrives at the scene
After beating up the criminals
Batman puts Rusty into an interrogation lock
Batman: Where's Freeze?
Rusty: You think I know?
Batman: You plan on celebrating the new year in traction?
Rusty: Okay, Okay! He made a deal with Penguin - weapons in exchange for some stiff - uh - Ferris Boyle. He's in GothCorp, last I saw.
Batman: You're lying! GothCorp doesn't make weapons.
Rusty: What!? No! I - GothCorp! I swear! Look - I've got the entry codes.
Batman: I'll take those.
Batman knocks Rusty out.
Downloading GothCorp entry codes
Batman: It doesn't make sense. GothCorp involved in weapons tech? There's got to be more to this.