Short-lived Danish imposter
Watched the film (yet again) on Christmas Day, as it is such a good film. However the Jackal only really used the Danish schoolteacher ID to board the train to Paris, after dumping the car of the lady he murdered overnight.
He left her mansion very early that morning (5.30am as per a clock in shot) after dying his hair and getting 'into' the Danish schoolteacher role. He drove off in her car, then he stopped remotely on a high road bridge and threw a suitcase away below, saying 'goodbye Mr Duggan'. The Jackal then parked up in a town from where he could catch a direct Paris train, and showed his Danish passport to a gendarme at the railway station.
NOW - on the train the Jackal had no contact with anyone (ie the OAS). Yet on arrival at Paris he did not ask the taxi driver to take him to a hotel, but to a turkish bath. OBVIOUSLY this was because he felt it too risky to book in anywhere with the Danish ID. But why? he was already in the taxi when he saw police cars whizzing to the station. So he must have been ultra intuitive not to risk using the Danish ID a second time.