From Galileo by John L. Heilbron:
p. 104 “On 21 April 1604, Silvestro Pagnoni, who had worked for Galileo for a year and a half as a copyist, presented himself ‘spontaneously’, which often meant, as in this case, on the urging of his confessor, before the nearest inquisitor. His conscience forced him to disclose that his former employer casts horoscopes.”
p. 104 “Pagnoni then enriched his testimony with some precious details about Galileo’s dealing with his mistress and his mother. During visit to Galileo in 1603/4, Guilia had enlisted Pagnoni to spy on his son. He duly relayed her confidences to the inquisitor:
I have understood from his mother that he never takes confession or takes communion, and she asked me to find out whether he went to mass on feast days. I observed that instead of going to mass he went to the house of his Venetian prostitute Marina.”
p. 105 “The Venetian authorities had no trouble to seeing that Pagnoni acted through spite and that his charges were ‘very frivolous and of no importance’. Galileo had to teach astrology; there was no reason that he should not practice it also; and Pagnoni certainly had not shown that Galileo interpreted the charts fatalistically. Galileo’s private life was no business for inquisition.”