Former New York police detective Chris Montanino remembers his frustration nearly three decades ago, when he was ready to go after child-porn distributors but couldn't find a prosecutor who would take his case seriously. Then he returned a call from a young woman at the local district attorney's office -- an intense, chain-smoking prosecutor known for working into the night, fueled by the caffeine buzz from a string of Tab diet sodas. When he got her on the line, he recalls, 'I blew my top,' complaining that his case -- he had purchased an armload of child pornography at a Manhattan bookstore -- had been passed from prosecutor to prosecutor without progress. 'This is baloney,' he said. The assistant district attorney, Sonia Sotomayor, cut short his tirade. 'You will be in my office at 9 a.m. tomorrow,' she said, then hung up. 'And that is the way it went,' Montanino said in an recent interview. 'She was no nonsense.' The five years Sotomayor spent in the Manhattan district attorney's office, say several friends and colleagues, shaped her as a criminal prosecutor and helped form her worldview as a judge. The experience, combined with her later years as a trial judge, would make her unique among her new colleagues at the Supreme Court should she be confirmed and would bring a firsthand exposure to the court's consideration of criminal procedure and sentencing. As a federal judge for 17 years at the district and circuit court levels, Sotomayor has written thousands of opinions, which now are receiving renewed scrutiny. The early examinations tell little about her jurisprudence on capital punishment, because it is rarely imposed in the states covered by the Court of Appeals for the 2nd Circuit, but so far have shown her as a middle-of-the-road jurist who, like most judges, rules most often in favor of the prosecution. 'She toes the line in terms of following what the law is, and in that respect (her opinions) come out as more pro-government,' said Ellen Podgor, a law professor at Stetson University who has reviewed about 100 of Sotomayor's appellate rulings in white-collar cases. Sotomayor arrived at the district attorney's office in 1979 from Princeton and Yale Law School, stepping off a path that had taken many of her classmates to white-shoe law firms and hefty paychecks. Instead she opted for the relatively low-paying position, telling friends she wanted the real-life experience, as well as a job that would allow her to try cases right away. With New York struggling financially and crime climbing to historic highs, the office was a gritty, frenetic place. In the faded art deco-style building, three and four prosecutors were squeezed into spaces designed for one. The intake room swelled with cops and crime victims. Metal desks were piled with papers and hemmed in by boxes of evidence. Sotomayor, described by friends as focused, intense and a perfectionist, labored to keep her desk an island of organization among the chaos. Dressed in inexpensive suits -- the only kind she could afford on her public servant's salary -- she prosecuted cases of disorderly conduct, public urination and graffiti. Within six months, she was promoted to handle more serious felonies, well ahead of her freshman class of prosecutors. Colleagues say she spent hour after hour studying the minutiae of her cases against murderers, armed robbers, child abusers and wayward cops. The attorneys were expected to juggle 80 to 100 cases at a time and, in her years there, Sotomayor tried perhaps 20 cases before juries. She survived by becoming, in the words of her friend Dawn Cardi, a 'caffeine addict' who started her day with a Tab, one of maybe 20 she threw back on an average day, along with a pack and a half of cigarettes. After staggering home to Brooklyn on the subway close to midnight, Sotomayor often stopped by Cardi's brownstone for a plate of pasta or pot roast and a glass of scotch. 'My baby would be asleep, and we would sit down and chat about our lives,' said Cardi, who was then a legal aid lawyer. The two women would marvel that their lives seemed straight out of prime-time television, full of petty crooks, tough-talking judges and courtroom drama. 'She angsted over all her trial cases,' Cardi said. 'She would sort of disappear into her work. You could have to remind her that she had to eat.' 'She was driven,' agreed former assistant district attorney Irving Hirsch. 'Definitely, driven and serious and competitive.' When she took on the pornography case, Montanino said, she was fun to work with, but she was also determined. She displayed no emotion when watching the grainy black-and-white films showing sex acts involving children ages 7 to 14, according to Karen Greve Milton, who helped with the prosecution. Jurors cried when they saw the scenes. Sotomayor ultimately won jail sentences for the store owner and a clerk. 'She isn't someone who lived her life in some ivory tower,' said Milton, now chief administrator in the court where Sotomayor is an appellate judge. 'She is somebody who grew up in the projects; she prosecuted cases that came from those areas, she saw how those cases devastated the victims. That informs her judgment.' -(Begin optional trim)- Cardi was a young, idealistic criminal defense lawyer in 1980 when she met Sotomayor. Cardi had just lost her first jury trial and was listening to the judge debate how much time her client should spend in jail. She was aghast -- her client was a 20-something father who had hit a subway rider with his umbrella and, in her opinion, deserved little more than a stern lecture. She worried that he might wind up behind bars solely because of her inexperience -- and the skill of the prosecutor, Sotomayor. But Sotomayor stood up and addressed the judge, saying in a self-assured tone that perhaps the defendant should be given probation instead. Cardi was stunned, knowing that a prosecutor's career could depend on appearing tough and winning stiff sentences. Cardi invited Sotomayor out for lunch, and they became good friends. 'A lot of district attorneys thought they were doing God's work. But she saw it as a civic responsibility,' Cardi said. 'She was also concerned that if there wasn't enough evidence, someone shouldn't be prosecuted.' Over time, Sotomayor saw that both the victims and the defendants in her cases were coming from poor neighborhoods. 'I had more problems during my first year in the office with the low-grade crimes -- the shoplifting, the prostitution, the minor assault cases,' she told a writer for the New York Times in 1983. 'In large measure, in those cases you were dealing with socioeconomic crimes, crimes that could be the product of the environment and of poverty. Once I started doing felonies, it became less hard. No matter how liberal I am, I'm still outraged by crimes of violence.' -(End optional trim)- Drew Ryce, a friend of Sotomayor's since law school, remembers visiting her when she was doing 'intake' at the office, meeting with police officers to decide what charges should be filed. 'It was very easy for a kid (prosecutor) to get pushed around by an old cop,' Ryce said. That day, an officer was urging her to not only file drug charges against a man who had been smoking marijuana in a doorway, but to add assault charges, saying the man had attacked him when he and his partner walked up. 'Did you sustain any injuries?' Sotomayor asked the officer, who replied that he had been cut on his knuckles. 'We'll just go with the drug charges,' the young prosecutor said, Ryce recalled. 'She didn't go all ACLU on the guy,' agreeing to file drug charges, but she also didn't defer to 'the system' and make a case out of scraped knuckles. By 1984, when Sotomayor left the prosecutor's office for private practice, 'she was a far better litigator ... she could take over a courtroom,' Cardi said. 'She saw the impact that crime had on our society ... she thought a lot about how we address it. ... As you get older and more experienced, it gets more complicated. You see shades of gray. I think she began to see these were complicated cases, they are not as simple as crime and punishment.' Staff writers Amy Goldstein and Jerry Markon and staff researchers Lucy Shackelford and Madonna Lebling contributed to this report. 