Using an Inquirer series as a road map, U.S. Sen. Arlen Specter said yesterday that he would preside over a Senate hearing in Philadelphia on Monday to explore how widespread witness intimidation has damaged the city's criminal justice system.

The witnesses are to include Police Commissioner Charles H. Ramsey, defense lawyer Michael Coard, and Richard Frei, a psychology professor at Community College of Philadelphia who has studied the phenomenon of witness noncooperation.

The hearing is the first in what Specter has promised will be a public examination of issues plaguing the city's court system.

"This is a good place to start," said Specter, referring to witness fear. "This is a very, very serious problem."

In a four-part series that began Sunday, The Inquirer has reported that witness fear is among a host of entrenched problems that have plunged the Philadelphia courts into crisis.

Based on a computer analysis of 31,000 criminal court cases filed in 2006, 2007, and 2008, the paper has shown that the courts are troubled by low conviction rates, an exploding caseload, a massive number of fugitives, and the dismissals of thousands of cases each year without weighing their merits.

Monday's installment chronicled how witness fear has come to pervade almost every violent-crime case. Terrified witnesses routinely fail to show up in court, and those who do often recant statements to police.

Specter, who switched parties and became a Democrat this year, served as a Republican district attorney of Philadelphia in the late 1960s and early 1970s.

In those years, he said, "we did not have this level of intimidation of witnesses. This is a very different picture."

As part of his fact-finding, Specter said, he has talked briefly with District Attorney Lynne M. Abraham. He dispatched a top Senate lawyer, Linda Dale Hoffa, a former federal prosecutor, to Philadelphia yesterday to interview Abraham.

"We're not wasting any time," he said.

Specter launched the inquiry by the Judiciary subcommittee on crime and drugs, which he chairs, within hours of reading the first part of the series on Sunday.

The hearing, open to the public, is scheduled for 9:30 a.m. Monday at the National Constitution Center, Fifth and Arch Streets.

Topping the list of witnesses is Ramsey, who formerly served as police chief in Washington. He has called the city's low conviction rates "very unfortunate."

Coard, the defense lawyer who will testify, represented a North Philadelphia man, Kareem Johnson, whose criminal history was explored in depth in The Inquirer's series.

Coard served as Johnson's attorney in a case in which he was convicted of killing a homicide witness. Johnson also was convicted of murder in the death of Faheem Thomas-Childs, a 10-year-old killed by cross fire in 2004. Johnson is now on death row.

Frei, the psychology professor, runs an effort he calls "the Snitching Project." He uses his students to explore the "anti-snitching" culture that exists in many city neighborhoods and makes it very difficult for police to find people willing to testify about crimes they have witnessed.

In a recent interview, Abraham described witness intimidation in the city as pervasive and growing.

She said her office's witness-relocation program was stretched to the limit. "We have lots of need and few bucks," she said.

For at least a decade, lawmakers in Congress have tried in vain to guarantee federal funding for local governments to protect and relocate witnesses.

Now, those efforts seem poised to succeed. A measure backed by U.S. Rep. Elijah Cummings, a Democrat from Baltimore, a city long troubled by violence against witnesses, is close to becoming law.

The bill would set aside $30 million annually to fund local efforts in each of the next five years. The measure passed the House, 412-11, this year, and an aide to Cummings said Senate passage seemed assured.