Even if it hadn't been the family business, Zenigata would have gone into the police force. From a young age, he saw that the world had rules and regulations and order. Follow the rules and everything turned out the way it should.
In school, you go through the lunch line and take one pudding cup and the entire class can have pudding. But once you start taking more than one, then the latecomers in the line are left with no pudding in the line. To say he never got pudding would be untrue, but he had experienced the feeling one too many times as he stared at other kids with three cups in front of them. It was then that he realized that a rule was only as strong as those who enforce it. He wasn't able to live his passion until he started college, studying law and judo and from there it was a hop, skip and jump to the Tokyo Metropolitan Police.

It might have been a whim, because of his last name, that he was assigned to a security detail on a museum Lupin had targeted. Whatever it was, he had no inkling of what that name would mean to him in the coming years. What did happen was he was the only one with a suspicion that something was wrong when everything looked right. He suddenly left his post to rush into the room with a priceless vase; a room that looked empty on the cameras but in reality was filled with the most audacious thing Zenigata had ever seen. A young man merrily grabbing antique art objects and tossing them out a window. When he saw Zenigata, he didn't look upset, remorseful or even annoyed. It was obvious that breaking the law, the rules, in front of the very personification of order was the highlight of the night. He grabbed another painting and leapt out the window, giving Zenigata a salute and wishing him farewell. Maybe it was because Zenigata was also the only officer who would dare leap out the third story window after Lupin that the request to transfer to Interpol went through so quickly.

But the man at the desk knows none of this. All he sees is an Asian man stagger up to his desk. His eyes are bloodshot yet piercing. They wildly check every corner in the room for something—or someone?—hidden. They come back to focus once again on the desk clerk, with a laser-like intensity that only the homicidal usually have. They stare into his eyes for reasons he can't fathom. Reasons he doesn't want to. He doesn't know that the hardest thing to disguise are the eyes themselves; many times Zenigata has been saved by this trick. The man with the wild eyes and trench coat rubbed his hand over his chin and the stubble of many days (weeks? months?) made a scratching sound as he seemed to prepare for something. Slamming his palms into the desk he started asking loudly for a man in a picture he was shoving in the desk clerk's face.
"Have you seen this monkey-face weasel?"
The desk clerk could only shake his head no in an attempt to get the man to leave.
Zenigata's hands started flailing wildly in the air to get his point across. "He usually wears a red jacket! He speaks Japanese with a French accent!"
"Sir, we're in New York…"
This almost brought Zenigata to a standstill. Almost.
"He probably speaks English with a French accent, too. But that doesn't matter!" he started to wave again. To finally catch the biggest affront to world order was all that Zenigata lived for. If that puny desk clerk thought that he could throw him off the scent, he was wrong. Lupin had been sighted in this area; Zenigata had given chase the day before. This hotel was in Lupin's preferred spot between high-life and downtown. It was the only place that sold his favorite cigarettes; Zenigata could smell the cologne he wore when he was staking out a place. Light, not too noticeable but nice enough to pick-up women. A sudden thought struck Zenigata.
"Look, he doesn't always look like this. He's a master of disguise! Sometimes he's a woman, or an Eskimo. You haven't seen anyone like this at all?"
Zenigata could tell the man was lying. The sweat trickling down his face was more than the usual reaction he got from scaring civilians. He suddenly grabbed the man's hands and inhaled.
"You've been paid money recently…At least $100. And these bills…They're stolen!"
The man paled. Zenigata knew he had him. Three years ago, Lupin had made off with a boatload of money from Germany. The money smell on the man's hands still had the distinctive sausage and beer smell German money had.

This man wasn't Lupin, however. He didn't have the right hands. Lupin's hands had more muscle mass from intricate lock picking; this man's hands were unused to manual labor. Zenigata's nose led him to the hiding place of said stolen money and he ripped out the man's pocket along with the items.
Oh well. All in the name of justice.
"Where did you get this from?
The desk clerk was whimpering, "Please, don't hurt me…"
Zenigata shook him. "I'm the police, you idiot! What makes you think I'm going to hurt you?"
All the same, Zeniagata let his lapels go and let the man back onto the ground.
"A man gave me this money if I didn't tell anyone he was renting a room here tomorrow."
Zenigata instant started wondering why Lupin would want a room the next night and not now…He grabbed the man again.
"Was he wearing a black tie or a pink one?"
"ANSWER ME!" he frothed, spitting into the man's face.
Zenigata let him down once more. Pink. The meant Lupin was having fish and going to the opera with a platinum blonde. Probably a model; could be an heiress. Zenigata started running though the list of available women he had memorized that morning when he felt a presence behind him. He turned around and loomed over one of the local men assigned to him.
Stupid louts the lot of them.
Couldn't tell Lupin's brand of whiskey from the cheap knockoff just by smell. How could they miss the astringency that only the good stuff had? How could they not notice that Jigen's cigarette smoke was slightly bluer? And they thought they could help him?
The man cowered in fear. He knew he was lucky Zenigata had felt him coming up behind him. The last officer who had tapped Zenigata on the shoulder had wound up judo thrown and pummeled within an inch of his life.
"Sir? There's been a sighting on 5th Street of a man in red blazer…"

Zenigata was off in a dead run before he had even finished, leaving the desk clerk still shaking in fear.

Slowly, from under the front desk, an Eskimo stood up with a gun pointing to the desk clerk.
"Very good, I wasn't sure you were going to make it a couple times there."
"I really don't want any part of this, please…"
The Eskimo laughed and walked away.
At the end of it all, the clerk wasn't sure who he was afraid of more.

A/N: Disco Ant said they never wrote Zenigata like a psycho, so I took up the cause. I should be writing more undead Jigen, but this was so much more interesting.