"Cold Case," the title of Kathryn Morris' hit CBS series, has never seemed so apt.

Over and over, the actress walks the same stretch of the Market Street Bridge, trading the same lines of dialogue with castmate Danny Pino. The Schuylkill River is frozen nearly solid, the temperature can't count to 10, and the wind is gusting so hard that the flags in front of the main post office are blown stiff.

Morris makes light of the conditions, saying, "It's a nice reminder of waiting out for (public transportation) when I used to live here." But her chattering teeth give her away.

Shooting outside in January is part of the price of creating a convincing series about a Philadelphia homicide detective. With Morris playing Lilly Rush, a cop dedicated to cracking murders that have gone unsolved for years, "Cold Case" has become the season's top-rated new drama, averaging more than 14 million viewers a week at 7 p.m. Sundays on CBS.

Normally, the series is shot at a studio in Southern California's Manhattan Beach, but during the Martin Luther King holiday weekend, the cast and crew flew here to film street scenes for several episodes.

Between takes, Morris, who turned 35 on Wednesday, huddles in the back seat of a Police Department SUV, the heater turned up high, to talk about the work that goes into "Cold Case."

"It was important to me to reflect the real police work these detectives do and the real emotional investment they place in their jobs," says Morris, who plays the department's only female homicide detective (actually, there are six). "They don't just punch in. They really invest their lives and their feelings in the closure of these cases, and in doing right by the families and by the victims."

Tim Bass, the Philadelphia homicide detective who serves as "Cold Case's" technical adviser, says, "She's very conscientious. She spent a couple of days with me and my partner just taking notes. She tries her best to do things the way we do, right down to demeanor and hand motions."

On television, image is often more important than substance. So despite how hard "Cold Case" strives for authenticity, many viewers want to talk only about Morris' funky, flyaway hair.

"Yeah," she says, with the tinkling laugh that punctuates her conversation, "the hair has become a show in itself."

"We purposely keep my hair not so coiffed so it works for this effortless, unstudied woman who is too busy doing cold cases to run to the salon," she explains. "She's a woman who eats real food and doesn't have a $500 hair-color job. Sometimes her roots are showing and sometimes her outfit isn't completely together. That's a character that has been missing from television."

Lilly Rush may be too harried for highlights, but that doesn't make her hard.

Series creator "Meredith Stiehm wrote such a great character," Morris says. "A woman who had a lot of strength but was never a bitch, a truly powerful woman but still feminine and compassionate."

Philadelphia Inquirer TV critic Jonathan Storm has praised Morris' "yeoman performance," saying she "brings along a little Julia Roberts when she grills her witnesses." The Washington Post's Tom Shales hailed her "insouciance, bravado and irresistibility. In two words: yum yum."

More than anyone else in the cast, Morris understands the local references in the scripts. "I know what the El means and I know the difference between Germantown and Cherry Hill," she says. That's because "Cold Case" represents a homecoming of sorts for her.

Born in Cincinnati, Morris had a nomadic childhood, singing with her family's gospel troupe. "It was very sweet," she says, "kind of 'Partridge Family'-like." After her parents divorced, the preteen Kathryn went to live with her father in Windsor Locks, Conn.

"When I was growing up, I was called Kathy Questions by my family because I was so inquisitive," she says. "It's funny, because now I play a character who asks a ton of questions."

She attended a now-defunct Christian college in Villanova, then transferred to Philadelphia's Temple University. "I lived ... in a rowhome with a bunch of other students. I walked and took the subway all over the city."

She used the income from a variety of part-time jobs to take acting classes and travel to Manhattan for auditions.

A faculty strike in 1990, during her senior year, persuaded her to drop out and take a chance on an agent in San Francisco who had encouraged her.

"I took a Greyhound bus with two suitcases and $60 all the way to California," she says. Within a week, she got an audition for a small role in "The Long Road Home," an NBC telefilm about the Dust Bowl. As soon as the casting directors saw her, they asked her to read for a larger part.

Morris believes that was a matter of breeding.

"It was a project about cotton pickers in the '30s," she says, "and that's where my folks are from. My family were early settlers in Oklahoma and Texas."

The TV movie jump-started her career, and she has worked steadily in Hollywood, especially lately. Her recent features include "Paycheck," with Ben Affleck, and the coming thriller "Mindhunters," with Val Kilmer.

Her TV work has included the recurring role of the villain Najara on "Xena: Warrior Princess." Each year, it seems, she shot a pilot for a prospective series. By her count, "Cold Case" was her 10th. Most of those never made it to the air, but one, "Sweet Justice" with Melissa Gilbert, was bought by NBC in 1994. But before the show premiered, Morris' character was recast with a black actress.

At least Morris got to attend the summer session where the networks introduce their new shows to the nation's television critics. Among the other NBC frosh that year were "ER" and "Friends."

"We were all sitting around talking about our pilots at the press tour: 'What's your show aboutfi' 'I'm a young lawyer and I show Melissa Gilbert the ropes. What's your show aboutfi'

" 'A hospital. What's yours aboutfi'

" 'Um, we're friends and we live in New York.'

"It was, like, a month later and those kids could not go grocery shopping" because they were getting mobbed by fans.

It took nearly a decade, but now Morris is getting a taste of what it's like to star on a hit show.

"I went to New York City over the holidays. I was thinking, 'I'll take a break. No one knows about my show.' I was trying to do this last-minute Christmas shopping frenzy, but everyone wanted to come up and talk about Lilly Rush. I'm thinking, 'I've got to get a gift out to my mom.' "

There's a tap on the window of the police wagon. Time for Morris to brave the elements again.

"It's great to come back and get a little bit of the flava," she says. "I love the culture and the food and the sense of community and the pride in Philadelphia."

Notice she didn't mention the weather.

This story appeared in The Daily Herald on page D2.

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