Details of Gentileschi's studio practice during this period have been preserved in the records of Tassi's trial. Following Caravaggio's lead, he often painted directly from models. One of the witnesses at the trial, Giovanni Molli, a 73-year-old pilgrim from Palermo, said that he had posed for several pictures around 1610–11, including a full length "St Jerome". Gentileschi also made studies from life for later use: he seems to have based the head of Abraham in the "Sacrifice of Isaac", painted in the early 1620s, on studies of Molli's head made more than ten years before.