PARANOIA

Just banging away:

* Fudged on the tests required for law enforcement, got caught, bribed out. Now under blackmailing.

* Confiscated an entire supply of illegal test subjects on their way to R&D. The test subjects are grateful, the organizers less so.

* Stole a detonator to something from the evidence. Someone needs it back as the evidence-locker has been opened and nothing has been taken.

* Your creche-bully who burned down the transbot didn't. You did.

* Instead of burning the ME-cards from the evidence, you took all 33 of them.

As of my own characters' skeletons: They made a corpse disposal firm and eradicated hunger in their complex in a certain awesome adventure.
 

1.> You went off the hormone supplements a few years back (an accident) and had a few exploratory encounters with a colleague. After they kicked back in, you had to make short work of said colleague to ensure that your record remained spotless. Or maybe you just parted ways sadly. Or maybe said colleague is now your partner. Or superior officer. Or maybe you have a junior citizen growing up in the Underplex that you have to care for by diverting food, clothes, and the like.
2.> There's just something about you... your smell, your genes, your voice, your thick Russian accent... that sets off IntSec Commie Detectors. That's why you ALWAYS handle and operate the squad Commie Detector personally. You have an impressively heroic number of captures and arrests on your record as a result.
3.> You (or a friend/ally) is a skilled Computer Phreak who did a bit of internal data routing to fast-track you from the food vats to the lofty position you're in now. Maybe your co-conspirators are expecting favors in return. Maybe there's a patch out there just waiting to blurt out the truth all over Friend Computer's memory... unless you can make your weekly payments.
4.> You have an unregistered and uncontrollable mutation that allows you to psionically explode people's heads when you are under stress, or startled, or excited, or haven't had any drugs in a few hours... in fact, your last 12 partners, and a good many of your arrest subjects, seem to have a habit of leaving headless corpses... the fact that you have kept it covered up so far is a testament to your ingenuity... but you are running low on excuses and ideas.
5.> Your rocketship promotion from the ranks of the Red Troubleshooters was the result of your (quite accidental) spectacular on-camera, live-feed termination of a high-ranking UV citizen who was secretly working to destroy Alpha Complex as an Illuminati/Free Enterprise cross-agent. That was two days ago. You sure hope nobody's holding a grudge.
 

6.> You keep receiving anonymous emails with attached photos of yourself in full communist regalia complete with furry hat and anarchist bomb, wherein you appear to be spraypainting "Down with The Computer" on a white wall. Did this actually happen? Maybe you can't remember. Maybe you were young and foolish. Maybe you're being set up. Maybe it was just another Friday nightcycle for you.
7.> You're a yellow striper. You read minds. IntSec is a fine place to make the best use of your talents... you are the squad's Thought Reader, the guy everyone turns to first to determine if a detainee is lying, the guy who smells danger before it's coming. Problem is, you're a fraud... as far as you can tell, you don't actually have *any* mutation, but you got framed a while back and tried to make the best of it. Word is some Anti-Mutants have a special disliking for your kind, and Psion doesn't tend to take well to "gene-traitors" either.
8.> Ever since volunteering for that medical testing program under the aegis of R&D's 'superagent' initiative, you have a habit of waking up naked, covered in sweat and blood, with no idea where you are or how you got there. The bodies on the floor aren't talking. Get yourself cleaned up fast, it's a good thing you'll be the one in charge of conducting the investigation!
9.> Your behavior makes Harvey Keitel seem like a paragon of good police service. You are plain bad. As in, corrupt. Bribery, drug running, gun running, random acts of sadism, blackmail... there's no way in which you haven't abused your position. Being a gifted Computer Empath has kept you in the clear so far. Problem is, some geek in CPU is rumored to have come up with a data-mining algorithm to seek out Computer Empaths with finality. Oops. Better get to work.
10.> You are IntIntSec. It's your job to keep an eagle eye on all these cheating scum and make sure none of them tarnishes the badge. It's not a nice job... sometimes rules have to be bent. Broken, even... that's fine, if justice and preservation of Alpha's ideals is the goal. Unfortunately, the spooks up at IntIntIntSec don't seem to agree, and are breathing down your neck a little. Gotta lay low for a bit.
11.> You had it made... your medical training and your spotless background meant candidacy in an elite Interrogations service firm (Truth B Told). Too bad about all the vomiting and passing out... you would have made a fine torturer. Now you walk the beat instead. Still, your past line of work meant you got to listen in on some very interesting conversations... you know a bit more about the internal workings of Alpha Complex than many might guess. Maybe too much. You're a bit worried someone will suddenly get around to remembering that.
12.> You have a standing policy of killing anyone who has known you more than a few weeks. Nothing personal, just a well-honed survival instinct and a few bad experiences in your past. When possible, you make use of the state aparatus to do your dirty work for you. People meeting you for the first time are generally impressed with how suave, happy, and empathetic you come across. It drives you almost berserk with rage when someone refuses to look you in the eye.
 

A few more, hope someone reads them this far back:

1 - It's occurred to you that your previous method of "Frame the rest of the team for mission failure and get promoted" isn't going to play so well in a place like IntSec. You sure hope no one figures out it was really you who screwed up every one of your previous missions.

2 - There's no polite way to spin this. You eat people. It's not your fault - you get headaches from eating algae. It started off when you were sent to cleanup a troubleshooter team that fell to infighting. But what started off as an occasional nibble on a misplaced limb turned into an active hobby of hunting down Infrareds who wouldn't be missed. You're tried to stop dozens of times. But the craving always returns.

3 - Free Market had to pull some serious strings to get you here, but they did it! Now they've got an inside line to all the contraband you can carry. Nobody keeps track of this stuff anyway. Right? Besides, it's wasted just sitting in boxes. This stuff should really be in circulation!

4 - You only got in here because you get your hands dirty. A higher level citizen got you into this position, but you're not sure why. Probably so you can help make more of his problems go away. You're not really interested in being in IntSec, and aren't very qualified in the first place. But if you look like you know what you're doing, maybe no one will notice.

5 - You were the only one in your dorm who wasn't a Romantic, but you went to the meetings anyway, so that they wouldn't haze you. But your life changed the day someone turned up with a full series run of an Old Reckoning show called TJ Hooker. That guy really knew what he was doing, and you learned everything about being in IntSec from watching that show. Once a week you meet with a few other people with similar obsessions over Old Reckoning Cop Shows. But your show is the best.

6 - Being in IntSec is mostly about shouting. As long as you can shout with authority, people will do what you say. In that regard, this position is a natural fit. As long as no one figures out you have a glass jaw and are terrified of combat, everything will go fine.