Last night's viewing - The Dark Charisma of Adolf Hitler, BBC2; Dispatches: Chinese Murder Mystery, Channel 4

As any historian knows, you need to know the origin and date of a piece of evidence before you know what it proves. Take this remark, for instance, about a man who eventually became so notorious that even the smallest fact about him would come to be of interest: "When I first met him he was like a tired stray dog looking for a master."

The subject of this condescending description – and of the film in which it was quoted – was Adolf Hitler. Its author was a Captain Karl Mayr, who recruited Hitler to propagandise against Communism among soldiers returning from the front. Mayr sent Hitler on a political education course at Munich University to help prepare him for this role. He later turned against his protégé, though, joining the Social Democrat Party. So it's at least possible that this is propaganda itself – an attempt to undermine the burgeoning myth of the saviour leader. Either way, it fits a cherished narrative about Hitler and it fitted well into The Dark Charisma of Adolf Hitler, Laurence Rees's three-part account of how the stray dog realised that he could be the master he was looking for.

Mayr, with a tragic irony given that he later died in Buchenwald, can probably claim a lot of the credit. Hitler's job – to hector disaffected soldiers about the importance of nation and the iniquity of Bolshevism and international Jewry – gave him a sense of mission that he never lost. He found he was good at hectoring, and that when he focused his innate rage others listened. A demagogue was born, and it was Rees's case here that the charisma he then developed was not an innate and destined genius (as Hitler himself wanted people to believe), but the result of a kind of unholy collaboration between dazzler and dazzled. What Hitler found he could supply – certainty, rage, the right kind of scapegoats – the German people were horribly eager to buy. They weren't hypnotised by him, Rees argues; they helped shape him into what they thought they needed.

The style of the thing is unsettlingly lurid from a director as scrupulous about television history as Rees. It employs CGI graphics to frame its archive, overlaying it with blooms of flame and verbal highlights. So when the voiceover notes that "Hitler had found his mission in life", the word "Mission" appears with a resonant crash, stamped across those famous features in blood-red type. Even more alarmingly, there are moments of dramatisation, although the dialogue remains untranslated from German and mercifully no one turns up as Hitler. But if you can overlook those slightly uncomfortable details, there is very gripping material here, some of it – and this is far more uncomfortable – gripping precisely because of Hitler's malign skill as a public speaker. In a fascinating piece of footage you see him about to deliver his first speech as Reich Chancellor, pausing for an extraordinary length of time until complete silence falls. That skill wasn't unique though – and watching this you can't fail to be aware that the conditions that allowed it to flourish are right now being replicated in Greece. As Brecht warned in Arturo Ui, "The bitch that bore him is in heat again...".

Chinese Murder Mystery, Dispatches' film about the murder of Neil Heywood, the British businessman who died in mysterious circumstances in a Chinese hotel room, did precisely the opposite of what such crime investigations usually do. The goal generally is to leave the viewer less uncertain about what happened rather than more. In this case, though, certainty suits the Chinese government, who found a culprit in the form of a party high-flyer's wife and had her tried and convicted in less than two days. In place of that dubious verdict – which helpfully stalled the career of the high-flyer – Dispatches restored a sense of just how dangerously murky politics in China can be. Gripping for all the right reasons.