Simplify the following text for a Grade 7 native English-speaking person.
Original: An enquiry was held but no attempt was made to arrest Donald Traill , master of Neptune and described as a demented sadist , or bring a public prosecution against him , the other masters , or the firm of contractors .
Simplified: An enquiry was held but no attempt was made to arrest Donald Traill , captain of Neptune . He had been described as an insane sadist .