Simon Briar was the brother of Minerva Trask. She considered him the best man the world had ever known and after he died, she cried every night for over a year. She did not have proof, but she believed strongly that he was murdered by Tim Shaw while foiling a burglary. Rachel Drummond said the money was the wages they had earned, but Reverend Gregory Trask and Minerva claimed that the money was to pay off their tuition when they were students at Worthington Hall (733).
The true circumstances surrounding Simon's death are recounted in the Big Finish audio drama The Crimson Pearl, where he was played by David Ames: Simon had stolen the titular pearl from where Gregory Trask had been hiding it (inside a hollowed-out Bible), but he was later surprised by Angelique, who killed him and took the pearl for her own purposes. Tim Shaw had come in just then, but Angelique used her powers to make him forget he had seen her.