The boys would be grown now, in their mid-30s, perhaps with children of their own. Instead, they're frozen in photographs and memories, brothers John and Daniel Jr., forever 3 and 4.

They died in the same bed in a 1985 Oxford Circle rowhouse fire that prosecutors say was set by their father, Daniel Dougherty - now being retried for murder and arson in Philadelphia Common Pleas Court.

Dougherty denies setting the fire, saying he loved the boys and tried to save them.

On Thursday, the horror of that August night more than 30 years ago came back fresh and full.

Over the objections of defense counsel, jurors were shown a single black-and-white photograph of the dead boys as they were found in the second-floor bedroom of their Carver Street home.

One juror grew teary when a medical examiner held up the picture. Another took a deep breath. At the defense table, Dougherty, 56, looked away and loudly blew his nose.

Some family members left the courtroom, or wept where they sat. The boys' mother, Kathleen Dippel, stepped into the hallway before the photo was shown.

The children were found covered in soot, clad in their underwear, both dead of smoke inhalation.

Dougherty has always insisted he awoke to a house ablaze, ran outside, then tried desperately to rescue John and Daniel. In 2000, he was tried, convicted, and sentenced to death.

Now he's counting on advances in fire science to free him.

He was granted a new trial when an appeals court ruled that his lawyer's failures so skewed the original proceeding that "no reliable adjudication of guilt or innocence took place."

Dougherty's trial lawyer, Thomas Ciccone, now deceased, never rebutted the state's expert testimony by calling a defense expert to describe improvements in fire science between 1985 and 2000, the appeals court said. The testimony of Assistant Fire Marshal John Quinn - now too ill to testify - was left unchallenged.

Quinn said the blaze was arson, with fires started on a love seat, a sofa, and beneath a dining-room table.

In court Thursday, Quinn's trial testimony was read to jurors. They were shown photo after photo of the charred interior of the home. Earlier they heard testimony that Dougherty was a drunk who hit both his live-in girlfriend, Kathleen Schuler, who owned the home, and his wife, Dippel, from whom he was separated.

Prosecutors say a vengeful Dougherty set the fire to hurt them both, destroying the house of one and the children of the other.

The main drama Thursday concerned the photos of the boys.

Defense attorney David Fryman argued that jurors would become incensed against his client if they were shown the graphic death-scene pictures.

"They're horrible," he said of the photographs.

The position of the bodies, Fryman argued, had no relation to the cause of the fire. Moreover, he said, the defense conceded that a fire condition called flashover did not occur on the second floor, where the boys died.

Assistant District Attorney Jude Conroy said the photos were important to show the scene as it was that day. They demonstrated, contrary to defense claims, that the original fire investigation was thorough and complete, he said.

If flashover had occurred, obliterating evidence, it would have scorched the entire house, not just the first floor, Conroy argued. The general lack of injury to the boys' bodies rebuts that contention, he said.

In flashover, rising heat collects at the ceiling, growing hotter until it radiates downward, causing parts of the room to spontaneously combust. That can make it difficult or impossible to determine where a fire started.

Judge J. Scott O'Keefe ruled that one photo of the dead boys could be shown to the jury.

Defense counsel also failed to keep jurors from hearing Quinn's original testimony. It had asserted that Quinn's lack of fire knowledge helped send Dougherty to death row.

During the last 20 years, a stream of scientific studies has deflated what once were considered solid indicators of arson. In Pennsylvania and elsewhere, inmates have challenged convictions that they say are based on old, disproved science.

Dougherty's death sentence was vacated in 2012, becoming a life sentence.

Prosecutors insist that the original guilty verdict was correct. They will continue presenting their case when the trial resumes Monday.

Dougherty was a 25-year-old mechanic at the time of the fire. He was charged 14 years later, in 1999, when his estranged second wife, Adrienne Sussman, then battling him for custody of their son, Stephen, called police and told them he had confessed to her.

She did not testify at his original trial and has since died.

Their son has attended the retrial every day, sitting behind his father.

"Love you, Dad," Stephen called out as Dougherty was led from court Thursday.

Dougherty turned to his son and blew him a kiss.