Voldemort, Snape, and Dumbledore are all skilled in Legilimency and Occlumency, albeit with the use of their wands. Voldemort is said to be the master of Legilimency by Snape, as he, in almost all cases, immediately knows if someone lied to him. In addition, in "Deathly Hallows", Voldemort repeatedly uses Legilimency to interrogate his victims. Voldemort practices Occlumency throughout the period of "Half-Blood Prince" to deny Harry access to his thoughts and emotions. However, in "Deathly Hallows", Voldemort repeatedly loses grip, resulting in occasional but very powerful burst of thoughts, visions and emotions to be sent to Harry.