It's a staple of pulp fiction and film noir: the sweating suspect, the good-cop bad-cop interrogators, and a confession extracted by crafty questioning, a glaring light, and some strategic smacks.

These aggressive questioning techniques - now frowned on by the courts - sometimes resulted in suspects confessing to crimes they did not commit. The stranger reality, say criminologists, is that physical coercion is not needed to obtain a false confession.

"It's incredibly counterintuitive how common false confessions are. It boggles my mind," said Peter Neufeld of the Innocence Project at Benjamin N. Cardozo School of Law in New York City.

Of 300 people freed through DNA evidence uncovered by the Innocence Project, Neufeld said, 25 percent had been convicted in part by their own false confessions.

"Twenty-five percent false confessions is a much higher number than I or anyone who is in the criminal justice system would ever imagine," Neufeld added.

Neufeld was one of several criminologists, psychologists, and lawyers who spoke Friday about the phenomenon of false confessions at a symposium for lawyers and legal professionals at Temple University's law school, sponsored by the Temple Law Review and the Temple-based Pennsylvania Innocence Project.

The experts said defense lawyers should be aware that even detailed confessions can be false.

Many people, especially those with cognitive or emotional-development problems, are especially vulnerable to being convinced that it is in their best interest to confess to a crime they did not commit.

The experts urged the legal community to push for videotaping police questioning of suspects - from start to finish - as a way of safeguarding criminal suspects who are vulnerable to confessing.

Richard Ofshe, a confession expert and sociologist at the University of California, Berkeley, showed a video of part of a New York interrogation that resulted in a contested confession of a man to the "shaken-baby" death of his 4-month-old child.

The detectives never laid a hand on the man, Ofshe noted, yet moved the conversation from general questioning to getting the suspect to agree to confess to killing the infant "to take the fall for my wife."

The infant died of sepsis - blood poisoning - Ofshe said, but the man's defense lawyer is still trying to get the confession thrown out.

Saul Kassin, an expert on false confession who is a psychologist and professor at John Jay College of Criminal Justice in New York City, said a confession - even a false one - corrupts the judicial process because investigators, prosecutors, and even judges begin looking at evidence in light of it.

Kassin said it is part of human nature to try to make puzzle pieces fit: "Confessions trump DNA."

Police questioning of suspects using lies and physical abuse used to be called "the third degree" and was seen as especially common in big-city police departments.

Philadelphia's experience with the consequences of the third degree reached a low point with the police investigation of a 1975 firebombing.

On Oct. 5, 1975, a firebomb was thrown through the front window of the Feltonville rowhouse of Radames Santiago, who had moved his family from Puerto Rico into a white neighborhood. Santiago's wife, three children, and a family friend died.

Police moved quickly to arrest, especially after a neighborhood teenager told police he had seen a red-haired neighbor, Robert "Reds" Wilkinson, pitch the firebomb.

According to a later federal indictment, police threatened and intimidated neighbors, and beat and questioned Wilkinson for hours before he signed a confession.

Wilkinson, then 27, was intellectually disabled and illiterate, married and a father. He spent 15 months in prison before a Pulitzer Prize-winning series by The Inquirer and a federal probe unraveled the injustice.

Wilkinson's conviction was overturned - a judge noted that he could not read the confession he signed - and he was freed and later settled a civil-rights suit against Philadelphia for $325,000.

The six police detectives who questioned Wilkinson were charged and convicted in federal court for violating his civil rights. Each was sentenced to 15 months.

Veteran defense attorney Louis Natali, now a Temple law professor, was a public defender at the time of the case. Natali said times have changed in Philadelphia. "They are much more sophisticated now," he said.

That hasn't resolved the issue.

In September, the Pennsylvania Supreme Court heard the pretrial appeal of Jose Alicea, 26, who has been in prison since age 19, when he confessed to the Oct. 30, 2005, shooting death of 21-year-old Esroy George Rowe during a melee at their neighborhood cafe in Olney.

Alicea's attorneys say he confessed not because he was guilty but because his low IQ and lack of experience with police made him especially vulnerable to questioning by authority figures.

Alicea's lawyers wanted to be able to have the jury hear testimony from Richard Leo, a University of San Francisco law professor and expert on false confessions who also spoke at Friday's symposium.

In Alicea's case, Philadelphia Common Pleas Court Judge Benjamin Lerner ruled that Leo could testify generally about factors that contribute to people falsely confessing.

The state Supreme Court justices gave no indication about when they would rule. Alicea remains in prison pending trial.

Contact Joseph A. Slobodzian at 215-854-2985 or jslobodzian@phillynews.com, or follow on Twitter @joeslobo.