Cases were coming and going, none sexy. Guilty pleas and bail hearings. Next, next, next. In capacious courtroom 160M, Judge C. Philip Nichols Jr. moved through the docket, not hurriedly, but not languidly. He was the day's "chambers judge," tapped to handle the elementary matters filtering into Circuit Court at the Prince George's County courthouse. By 3 p.m., Nichols had surfed through 19 tales of burglary, drug use, failure to pay child support and other alleged misdeeds.

"That's it, your honor," a clerk said, finally.

It had been a plain-wrapped Tuesday that obscured the gambles Nichols had taken. Each time he had signed off on a mild bail or sentence--each time he didn't throw the book--he was betting a defendant's future conduct would be salutary. He calls this "walking in a minefield."

"Next thing you know," he said, "it's your worst nightmare."

His happened in June, when Keith Arnez Boone was charged with murder in the death of a Capitol Heights woman who was killed by a wayward slug from a street shooting as she hung curtains in her house. Five months earlier, Nichols had sentenced the alleged shooter--Boone--to home monitoring instead of jail after he pleaded guilty to a drug charge.

Such headline-generating cases might be a reason why the Maryland Commission on Criminal Sentencing Policy found two years ago that "less than one-third of Marylanders believe that the state adequately punishes offenders," and that 60 percent believe "judges who are too lenient" are a cause of crime.

Reacting to reports that a judge had allowed a man who smothered his son to move from a state mental hospital to a halfway house from which he fled in October, Montgomery County State's Attorney Douglas F. Gansler said, "The real issue is, why do we have a judicial system that allows someone like this to be out on the streets?"

Spend time with Nichols, however, and images emerge of a congested legal system that cannot possibly lock up every criminal and of judges relying on experience, prosecutors, sentencing guidelines and instinct to gauge what to do with those convicted and charged. It is, Circuit Court Judge Steven I. Platt said, a "risk-assessment business." Inevitably, some evaluations come back to haunt the evaluators.

"To any judge who's been there any length of time, this happens," said attorney Timothy Maloney, a friend of Nichols. Any sentence or bail, Maloney said, is "a judgment call, and a gut call, and a judge is asked to know the unknowable, and that is: 'What is this person's behavior going to be like a month from now, a year from now?' "

In fiscal 1998, 44,239 cases poured into the Prince George's County Circuit Court, of which 9,524 were criminal. The 23 judges, therefore, averaged 1,923 civil and criminal cases apiece, or more than seven new ones every week day. Although 95 percent never reach trial, because of settlements and plea bargains, each case generates paperwork, takes time and often requires a plethora of rulings.

Bill Grant, a retired military judge whom Nichols met while in the Navy Reserve, said "everyone worries that they did the right thing" with cases. "But at some point," Grant said, "you do have to move on. I have these other cases to worry about. I cannot dwell on the one from yesterday. There is a volume issue. You make the best call."

"This is," Nichols said, "a busy place."

And never more so than in the courtroom of the day's chambers judge, a duty Nichols draws once or twice a month. The job is notable for how little a chambers judge knows beforehand about the matters he or she will hear, be they criminal pleas and sentencings, bail hearings or requests for search warrants or restraining orders.

"It's probably the most intellectually challenging day that exists," said Ernest A. Loveless Jr., former chief judge of the Prince George's Circuit Court, "because you've got to jump on so many different things that are not related, that you've never even seen before."

Taking the bench at 10:03 a.m. on the recent Tuesday, Nichols began hearing the first of six pleas of guilt, each with its own cast and its own blue-covered file handed up to him by a clerk. Nichols, 52, a native son of Prince George's County and a judge for 14 years, steered the proceedings with an even-toned voice, dry wit and informality.

"You a little scared?" Nichols said to a young defendant.

"I'm a little nervous."

"Are you pleading guilty because you are guilty?"

He was. Nichols explained that meant there would be no trial, no chance to grill witnesses. He asked if the defendant understood. He did.

"Let's hear the facts," Nichols said.

A prosecutor synopsized: A 1983 Blazer had no front tag. An officer stopped it in Lanham. The officer caught a whiff of marijuana from inside the Blazer. Marijuana was found.

"I'm going to impose sentence now," Nichols said, and did: one year, suspended, and 20 hours of community service.

It was the result both defense and prosecution had sought. Nichols can reject a plea bargain, and would "if it just shocks your conscience and it's that far off the charts." But generally, he said, a judge takes the advice of the prosecution and defense. They know the case, whereas the judge has "30 seconds invested into it."

On Jan. 11, Nichols was presented with just such a plea bargain in the drug case of Keith Arnez Boone, 21, who had had brushes with the law, according to court records, but apparently no convictions. According to Boone's attorney, Douglas J. Wood, the state agreed to a "standard" sentence of probation and home monitoring in return for a plea of guilty to a charge of possession of cocaine with intent to distribute. Nichols signed off on the arrangement.

Five months later, police say, Boone tried to shoot a man in retaliation for a drug deal gone bad, and the bullet killed Dona Elizabeth Ferguson, 40, as she stood in her home. The private firm that was supposed to keep tabs on Boone in connection with his January sentence, Home Tracking Inc., has announced it will go out of business, after reports that it was responsible for 98 percent of all house-arrest violations reported by private firms in Maryland in July and August.

"Mr. Boone was a run-of-the-mill drug case," Wood said. "There was nothing spectacular. He got a disposition that hundreds of guys have gotten. . . . I think most judges up there would have given Mr. Boone what Judge Nichols did."

In weighing a decision, Nichols said, he considers a defendant's criminal record and whether a weapon was involved; takes into account the prosecution's wishes; and looks to sentencing guidelines that give him a range of punishments. Any decision about incarcerating someone is made against the backdrop of a Maryland prison system that, last year, held more than 20,000 people, the 14th-highest rate of incarceration in the United States.

"There are 200,000 people out there eligible for 20,000 rooms in the hotel," Maloney said, refering to Maryland's criminal defendants and available prison cells, "and he [Nichols] and every other judge has to decide which 10 percent get the rooms. . . . If you incarcerated every person in the state who committed a felony every year, you'd be building the equivalent of a new NFL stadium every year."

Once he makes a ruling, Nichols said, he doesn't mentally revisit it. "You can't be a decision-maker if you're going to second-guess your decisions," he said in his chambers, a quiet refuge bathed in soft classical music and stocked not only with legal tomes, but baseball caps and coffee mugs sporting the insignia of military outfits, the souvenirs of Nichols's reserve duty.

Nichols knows of only two decisions in 14 years on the bench that were followed by his "worst nightmare." The Boone case is one. The other, Nichols said, was a case "in which everybody wanted someone released on bail . . . and he went home and murdered his wife."

"If I made some conscious decision that ultimately resulted in some innocent being hurt or killed," Nichols said, "that would just be a terrible thing."

Toward the end of the uneventful Tuesday, Nichols was trying to decide on bail for a man locked up for allegedly failing to pay $23,000 in family support. The defendant, appearing via a TV monitor from jail, begged to be released so he could report to his new, well-paying job, which would allow him to start making the payments he owed.

Nichols seemed dubious. But the defendant's minister, who had come to court, said he would vouch for him.

"All right, the reverend's going to stand behind you," Nichols said. "I'm going to take a chance."

CAPTION: Judge C. Philip Nichols Jr., in his chambers in the Prince George's County Courthouse, says judges can't afford to second-guess themselves.