By Saskia Rowlands A professor who campaigns to free Lucy Letby was allowed to lecture students near the hospital where she murdered babies. Academic Richard Gill claims prosecution evidence was bogus and trolls an NHS doctor who helped secure the serial killer’s conviction. But Gill’s alarming web posts did not deter Liverpool University from inviting him to lecture. It is 17 miles from the Countess of Chester Hospital, where Letby was a nurse. Gill, 72, a professor of statistics, travelled from his home in Holland for the class at the department of mathematical scientists. Although he did no…