In his new UPN sitcom, John DiResta plays a New York City transit cop.

Seven months ago, John DiResta was a New York City transit cop.Which is a little unlikely, even for the not-quite-a-network UPN.

"About six years ago, I was flat broke, had two kids, a job I could not stand - which was being a transit cop in New York City," DiResta said. "It was lonely. It stunk. I always wanted to do stand-up, and all these forces came together. I did my first open-mike show about six years ago this month. And then did a one-man show. The one-man show got a lot of good reviews, and we made it into a sitcom."

It wasn't quite that easy, of course. And it didn't happen all that quickly. But DiResta was definitely looking for something more in his life than a career as a transit cop.

"To put it bluntly, you were treated like (expletive) as a cop. . . . The pay sucked. You went out, you stood in the subway for 12 hours, you went home," he said.

And it wasn't the most fulfilling of careers.

"You went home say, `Oh, wow, I gave someone directions today. Yeah!' " DiResta joked. "There were four statements you needed to survive as a transit cop - `Up the stairs to your right'; `Two blocks down on your left'; `Yes, we carry guns'; and `It's only a flesh wound.'

"I was a very depressed guy being a cop, I guess. Maybe that made for good comedy."

DiResta didn't actually quit as a transit cop until March of this year after putting in a dozen years on the job. Much of that time was spent working with the homeless - getting them out of the subways, trying to find them a place to stay, food to eat and clothes to wear.

"I got into a unit called the Homeless Outreach Unit where we help homeless people," DiResta said. "I worked 9:30 at night until 6 in the morning" for the last seven years of his stint as a transit cop. And it was there that he began to hone his comedy talents.

"We'd have a whole bus full of clients - that's what we'd call them, our homeless people - and I had them laughing every night. We had a great time," he said.

Eventually, his partner noticed an ad in the Village Voice that read, "Comics wanted. No experience necessary." And he urged DiResta to give it a try.

"I got home at 7 in the morning, dead tired, and said to my wife, `I want to be a standup comedian. That's what I want to do,' " DiResta said. "She said, `I want another baby.' So now we have three."

And DiResta began making the rounds, working dates for little or no money, even taking a job as a clown.

"That was brutal. . . . Eight hours in a clown outfit. It was horrible," he said. "You ever try going to the bathroom in a public stall with size 331/2 shoes sticking out from underneath with 40 kids banging on the door?"

But, eventually, his stand-up act got him noticed. Particularly that one-man show, which he performed off-Broadway.

And his success in comedy made his job as a transit cop more bearable.

"When I found comedy as a release, I actually liked the homeless outreach unit," DiResta said. "I did not hate it. I mean, I like this now better."

A trip to Hollywood got him a sitcom development deal, which turned into "DiResta." But it was only after that was all signed, sealed and deliver that he finally quit his job on March 27.

"It was actually nine months and five years later, the day I resigned the police department," DiResta said. "My daughter's fifth birthday was my last day as a cop."

And, so far at least, "Everyone has been very nice to me."

Not to mention the fact that he's making a bit more money.

"Yeah, I'm making more money, but you know what's nice? We did promos the other day for 12 or 15 hours. I don't know these cameramen. I don't know these grips," he said. "I don't even know what a grip does, but at the end of the day everyone clapped when we wrapped because it was a team effort.

"No one ever clapped at the end of the day when you worked as a transit cop."

Still, the additional money is great - particularly for someone who has scraped by for so long, living paycheck to paycheck.

"When my son lost his first tooth, about four years ago, I was so broke I didn't have a dime on the face of the earth," DiResta said. "I put a post-dated check under his pillow signed `The Tooth Fairy.'

"I used to have to beat the fare on the George Washington Bridge on a regular basis. . . . I did it for months 'cause I was just so broke."

Things are, of course, a bit better these days.

"I got a convertible Mustang. I rent a house in Studio City. I have my own little tiny office now," DiResta said. "The one thing I'd like to do is buy my kids their own computer. Because I just got into the computer about a year ago and they're all over it. Every time I go to use it they're playing the computer games."

As to whatever money he makes from the sitcom, "I'd like to just save it and have some," he said.

"It's nice. Now when I go to the ATM I take out a hundred at a time instead of 20. I mean, that's a big difference," DiResta said. "You know, it's nice to know that when you write a check you don't have to connect something to it like, `Can you hold it for a week?' "