Seventeen years in state prison haven't done much for Daniel Dougherty.

He limped into the courtroom Monday morning, leaning heavily on a wooden cane, his long hair pulled back in a ponytail. He wore a gray jacket and a frown.

He's gained weight since 2000, when he was tried, convicted, and sentenced to death for the murder of his two young sons in an arson in the family's Oxford Circle rowhouse in 1985.

Dougherty has always insisted on his innocence. On Monday in Philadelphia Common Pleas Court, he took a new chance to prove it, his retrial ordered by an appellate court that found his lawyer's failures so skewed the original proceeding that "no reliable adjudication of guilt or innocence took place."

Testimony over advances in fire science will play a crucial role in the retrial, which is expected to last at least a week.

Dougherty, 56, entered court as the lawyers were to discuss pretrial matters with the judge. It wasn't long before he spoke up - after a sheriff's deputy told him not to turn around and speak to family members seated behind him.

"Ain't I an innocent man?" Dougherty demanded of Judge J. Scott O'Keefe. "I haven't been proven guilty."

The judge admonished Dougherty to face forward. Later, as Dougherty was led out during a recess, he called to his adult son, Stephen, "You look good, man. Love you!"

"Love you, too," Stephen Dougherty responded.

All-day questioning produced a jury of nine women and three men, with three alternates to be chosen Tuesday.

The jury includes a woman who said she has strong doubts about the veracity of police officers because of her drug-addicted brother's recent arrest. She also once accidentally set her home on fire.

Others include a tax accountant, a forklift operator, a jewelry designer, and a rail conductor who was sure he had read nothing about the case in newspapers because "I only read the sports."

Among those excused from serving was a woman whose father was a Lancaster-area firefighter, and a teacher who said he becomes so distressed about cases or images involving harm to children that he's still upset by a perilous scene in Titanic.

Before the jury was chosen, defense lawyer David Fryman and Assistant District Attorney Jude Conroy sparred over whether the prosecution could introduce a photo of the dead children, ages 3 and 4, taken in their second-floor bedroom after the fire.

Fryman argued that at the first trial, prosecutor John Doyle agreed to exclude the photos and none was admitted.

"Things have changed," Conroy said. "The defense is putting on an expert." The position of the boys' bodies, he said, is relevant to a fire condition called flashover.

Fryman answered that nothing about the bodies or their physical condition was relevant to that.

Fire authorities say that in a flashover, rising heat collects at the ceiling, with the air growing hotter until it radiates downward, causing parts of the room to spontaneously combust. That can make it nearly impossible to know the starting point or points of a fire - a core question at Dougherty's trial.

The judge made no immediate ruling on the use of the photos of the boys, who died of smoke inhalation.

Dougherty's new lawyers, Fryman and Shannon Farmer, both of Ballard Spahr, have indicated they plan to present expert testimony to show that Dougherty was convicted on junk science.

Expected to take the stand is nationally known investigator John Lentini of Scientific Fire Analysis L.L.C. in Florida, who has said the cause of the blaze should have been ruled "undetermined."

The extensive damage to the rowhouse, he wrote in a report for the defense during the appeal, made it impossible to determine where or how the fire started. What's sure, he said, is that the evidence did not show three separate points of origin, the basis for the prosecution's conclusion of arson.

Dougherty was not arrested until 14 years after the fire, in 1999. That's when his estranged second wife, Adrienne Sussman, then battling Dougherty for custody of their son, called police and told them he had confessed to her. She never testified.

Dougherty's death sentence was vacated in 2012, becoming a life sentence, after prosecutors agreed with the defense on the ineffectiveness of his trial lawyer, Thomas Ciccone, who is now deceased.

215-854-4906 @JeffGammage