On 10 July 1584, as William the Silent climbed the stairs to the second floor, he was spoken to by the Welsh captain Roger Williams, who knelt before him. William put his hand on the bowed head of the old captain, at which moment Gérard jumped out of a dark corner. He drew his weapons and fired two shots at the stadtholder. William the Silent collapsed. His sister knelt beside him, but it was too late. Asked whether he commended his soul to Christ, he answered in the affirmative. His last words were, Mon Dieu, ayez pitié de moi et de mon pauvre peuple ("My God, have mercy on me and on my poor people").
Gérard fled through a side door and ran across a narrow lane, pursued by Roger Williams. Gérard had almost reached the ramparts, from which he intended to jump into the moat. On the other side a saddled horse stood ready. A pig's bladder around his waist was intended to help keep him afloat. However, he stumbled over a heap of rubbish. A servant and a halberdier of the prince who had raced after him caught him. When called a traitor by his captors, he is said to have replied, "I am no traitor; I am a loyal servant of my lord." "Which lord?", they asked. "Of my lord and master, the king of Spain". At the same time more pages and halberdiers of the prince appeared and dragged him back to the house under a rain of fists and beatings with the butt of a sword. Hearing his assailants chatter and convinced he heard the prince was still alive, he cried "Cursed be the hand that missed!"
At the house he immediately underwent a preliminary examination before the city magistrates. Upon being interrogated by the magistrates, he reportedly showed neither despair nor contrition, but rather a quiet exultation, stating: "Like David, he had slain Goliath of Gath."
At his trial, Gérard was sentenced to be brutally – even by the standards of that time – killed. The magistrates decreed that the right hand of Gérard should be burned off with a red-hot iron, that his flesh should be torn from his bones with pincers in six different places, that he should be quartered and disemboweled alive, his heart torn from his bosom and flung in his face, and that, finally, his head should be taken off. Gérard's torture was also very brutal. On the first night of his imprisonment Gérard was hung on a pole and lashed with a whip. After that his wounds were smeared with honey and a goat was brought to lick the honey off his skin with his rough tongue. The goat however refused to touch the body of the sentenced.
After this and other tortures he was left to pass the night with his hands and feet bound together, like a ball, so sleep would be difficult. During the following three days, he was repeatedly mocked and hung on a pole with his hands tied behind his back. Then a weight of 300 metric pounds (150 kg) was attached to each of his big toes for half an hour. After this half hour Gérard was fitted with shoes made of well-oiled, uncured dog skin; the shoes were two fingers shorter than his feet. In this state he was put before a fire. When the shoes warmed up, they contracted, crushing the feet inside them to stumps. When the shoes were removed, his half-broiled skin was torn off. After his feet were damaged, his armpits were branded. After that he was dressed in a shirt soaked in alcohol. Then burning bacon fat was poured over him and sharp nails were stuck between the flesh and the nails of his hands and feet. Gérard is said to have grown frantic during his torture. On 14 July 1584, Gérard was executed.
