The jury had been selected, the bailiff had told everyone to turn off their cellphones and swallow their chewing gum, and a prosecutor turned to address the defendants.
"You are charged," intoned Jude Conroy, "with the murder of one million Irish peasants."
The jury was an English class from St. Joseph's Preparatory School; the prosecutors, local attorneys and law students taking a morning off; the charges, a better fit for the Hague than a City Hall courtroom.
But this weekend, the city is host to an international convention sponsored by the Irish government and focusing on the Great Famine of 1845. After the country's potato crop failed, a million Irish people died and another million left for abroad.
Hence Friday's mock trial, with Municipal Court Judge Patrick F. Dugan officiating and Prep students standing in for the jury and the defendants - the British government and its proxies in Ireland, which Britain then ruled.
The counts of the indictment: allowing landlords to squeeze rent out of suffering tenants, passing ineffective relief measures, and continuing to export grain even as millions starved.
The political climate surrounding the famine, said James Murphy, the director emeritus of Villanova's Irish studies program, still resonates.
"There were arguments over subjects like immigration, prejudice, poverty, and hunger," he told the courtroom. "Sound familiar? "
The participants took their roles seriously.
"This is the greatest empire that ever existed in the world, and these allegations are ridiculous," spat out Michael Fenerty, a Center City lawyer defending the Crown.
"Hypocrisy!" the prosecutors crowed.
"There's a whole empire to feed," Fenerty countered.
The students in the jury box paid careful attention. Dugan explained to them the concept of reasonable doubt before they left the courtroom. They deliberated for about five minutes before returning with their verdict.
"Guilty on all counts," the foreman pronounced. The courtroom applauded.
Bob Gessler, vice president of the National Irish Memorial, which organized the event, said the mock trial was his first. He had borrowed a classroom exercise from a teacher in Oregon.
"I didn't have much of a knowledge of the potato famine," said Anthony Amato, 16, a junior, "and it'll be a good introduction to what we study this spring."
Next semester, the class will read a selection of Irish literature.
Dugan said that he was pleased with the verdict - as a Philadelphian of Irish descent, not as an officer of the court. He was careful to remind the jurors, as they filed out of the room to board school buses back to fifth period, that a real trial on the murder of a million civilians would have taken years.
"I just want to reiterate," he said, "that we cut a tremendous amount of corners today."
Fenerty packed up his bags in the corner of the room. An Irishman himself, he had nonetheless gotten into the act on behalf of the Brits.
"Once I started arguing," he said, "I wanted to win."