Princes in the Tower "the murther of his nephews towards the world", indicating that the boys did indeed meet their end during Richard's days. It is also unlikely that the princes would have been kept alive in secret by Richard for 2 years after their last sighting while rumours of his responsibility for their murder circulated. Some writers have also accused John Howard, 1st Duke of Norfolk; Margaret Beaufort, Henry VII's mother; and Jane Shore (Edward IV's mistress). Pollard writes of these theories: "None deserve serious consideration. The problem with all these accusations is that they beg the question of access to the Tower
Princes in the Tower to the throne. Shortly before his execution, Tyrrell is said by Thomas More to have admitted, under torture, to having murdered the princes at the behest of Richard III. The only record of this is the writing of Thomas More, who wrote that, during his examination, Tyrrell made his confession as to the murders, saying that Richard III ordered their deaths. He also implicated two other men; despite further questioning, however, he was unable to say where the bodies were, claiming that Brackenbury had moved them. William Shakespeare portrays him as the culprit, sought out by Richard after Buckingham demurs.