Her voice cracking and her eyes welling up with tears, Dolores Roberto testified at a state Senate hearing yesterday about Thanksgiving night 2004, when a drunk hit-and-run driver killed her son, leaving him lifeless in the middle of Harbison Avenue.

"I remember running the three city blocks from my parents' house to the crash scene as if it was yesterday. . . . I remember identifying my son's body. . . . I remember the police officer telling me that the driver had fled."

She recalled "sitting on the cold ground, rocking back and forth, wondering how I was going to tell my husband and how we, as a family, were going to go on without him," referring to their 12-year-old son, Peter Roberto Jr., who was killed by William Halloran at Harbison Avenue and Comly Street in Wissinoming.

Dolores Roberto, 40, and another mother who lost a child in a hit-and-run, Theresa Sautter, 42, urged senators at the Senate Transportation Committee hearing, held at Nazareth Hospital in Northeast Philadelphia, to stiffen the penalties on drivers who flee the scene of a crash.

"Our lives were turned upside-down forever," testified Sautter, whose daughter, Marylee Otto, 15, was hit by driver Michelle Johnson on March 28, 2008, at Rhawn Street and Lexington Avenue in Northeast Philadelphia.

"We want to see the laws changed," Sautter said.

Sen. Michael Stack, D-Phila., who organized the hearing, has sponsored a bill (Senate Bill 522) to increase from one to five years in prison the mandatory-minimum sentence for someone who flees the scene of a fatal accident. If the victim suffers serious injury, the bill would raise the mandatory-minimum sentence from 90 days to two years.

Transportation Committee Chairman Sen. John Rafferty, a Republican who represents parts of Chester, Montgomery and Berks counties, has co-sponsored the bill and is the lead sponsor of another bill (SB 1177) that would increase the minimum prison time to two years if someone flees a deadly accident, and to one year in the case of serious injury.

Two other Senate bills have been drafted, including one by Sen. Larry Farnese, D-Phila., that would provide other penalty options that the committee could consider before the issue comes to a vote.

Philadelphia Police Capt. Michael Murphy, of the Accident Investigation Division, testified before Stack, Rafferty and Farnese that "the current penalties are no longer impacting criminal behavior." He said he believes "most drivers leaving the scene of accidents do so because they are under the influence of drugs and/or alcohol."

State Police Lt. Anthony Sivo also told the senators that many people tend to flee the scene because of an underlying reason - they're intoxicated or they're wanted for another crime.

The law-enforcement officers and Assistant District Attorney Michael Barry agreed that people who are intoxicated have an incentive under current laws to flee the scene, hoping they won't get caught before their bodies metabolize the alcohol or drugs.

Without evidence that a person was intoxicated, it is "extremely difficult" for prosecutors to prove it, Barry said.

The D.A.'s office supports increasing mandatory-minimum sentences, but Barry said his office also wants the ability to waive mandatory minimums as part of sentence negotiations, particularly in cases in which the evidence is not strong.

Otherwise, he said, a case without strong evidence might go to trial, and a jury could acquit a driver who was guilty.

In Pennsylvania, it is now a third-degree felony if a driver flees the scene of an accident that causes serious injury or death, and a misdemeanor for a nonserious injury. Among proposals in Farnese's bill is one that would make any hit-and-run case involving injury a felony.