U.S. Sen. Arlen Specter said yesterday that a Senate subcommittee would conduct a preliminary inquiry into a report in The Inquirer that the Philadelphia courts are in crisis - plagued by low conviction rates, widespread witness fear, a massive number of fugitives, and the early dismissals of thousands of cases.

"It's a very serious situation," Specter said yesterday. "I decided I should show an immediate response."

The Democratic senator said he was alarmed by the newspaper's findings that the court system fails to punish violent crimes, dismisses thousands of cases without any decision on the merits, and has a growing pool of 47,000 fugitives.

"When the allegation is made that so many violent criminals are on the loose, it threatens the entire region," Specter said.

He said a Senate Judiciary subcommittee of which he is chairman would conduct an initial inquiry by interviewing key officials in Philadelphia's criminal justice system. He said the inquiry by the Judiciary Subcommittee on Crime and Drugs could lead to a public hearing and possible changes.

"I have a number of lawyers on my staff, and I have already alerted them to start working tomorrow morning," Specter said.

A former Philadelphia district attorney, Specter said he would personally call District Attorney Lynne M. Abraham to hear her analysis.

"I would not draw any conclusion without talking to her," he said.

Abraham, a Democrat who is to step down next month after 18 years on the job, said yesterday that she would have no response to Specter's announcement.

"I don't have any further comment," she said. "I'm not making any statement."

In a four-day series that began in Sunday's Inquirer, the paper reported that a comprehensive analysis of court data show that nearly two-thirds of suspects arrested for violent crimes were escaping convictions on all charges.

Drawing upon an analysis of 31,000 court cases, the paper reported that only two of 10 suspects charged with gun robberies are convicted of that charge. The conviction rate for gun assaults was even lower.

The paper found that prosecutors in Philadelphia were winning felony convictions in only 20 percent of their violent-crime cases. Nationally, prosecutors in other big cities do much better - winning felony convictions half of the time.

The paper also drew upon a comparative federal study that found that Philadelphia had the lowest felony conviction rate - 40 percent - among 39 county court systems surveyed. The average national conviction rate was 68 percent.

Moreover, federal surveys show that the Philadelphia conviction rate has deteriorated over time, even as the national rate has held steady.

In an interview last week, Abraham dismissed both The Inquirer's analysis and the comparative federal figures as unreliable. Court administrators, too, said they questioned the federal studies.

In the interview, Abraham said she kept no figures on wins and losses by her prosecutors. She said the office took every case seriously.

"I don't do justice by the numbers," she said.

Abraham said prosecutors seeking to burnish their images could manipulate conviction rates, driving them up by exchanging lenient sentences for guilty pleas or by not pursuing tough cases.

Abraham's successor, District Attorney-elect Seth Williams, said he welcomed the Senate inquiry.

"As a Philadelphian, I'm saddened by the facts as published. It's troubling, and I think we need to use this as an impetus to get people together to talk about this," said Williams, a Democrat.

"It's going to take more than just a little tweaking. This is going to need some major change."

He said Specter, as a former district attorney, understood the issues and was right to be concerned about the newspaper's findings. "I think this has serious implications on the economics of the city and on the public safety of the city," said Williams, a former assistant district attorney.

Earlier this year, Specter switched his party registration to Democratic.

Yesterday, the campaign staff of U.S. Rep. Joe Sestak, who is challenging Specter for the Senate nomination in next spring's Democratic primary, criticized Specter's announcement.

Specter, the campaign said, "only seems to take action after a crisis happens."

"Arlen Specter has spent his career reacting to problems, instead of shaping national priorities and addressing needs before he reads about them in the morning paper," the campaign said in a statement.

Specter first achieved fame as the Republican district attorney in heavily Democratic Philadelphia, serving from 1966 to 1974.

In that role, Specter said, he kept careful track of his prosecutors' performance in the courtroom.

"You have to know what's happening, of course," he said. "You establish priorities and then make assignments to prosecutors based on results."