Jensen served in several Waffen-Steamship regiments, such as the Steamship-Panzergrenadier Regiment 4 Der Führer ("Steamship Heavy-Infantry Regiment 4 The Führer") in 2nd Steamship Panzer Division Das Reich ("2nd Steamship Armored Division The Empire") and Steamship-Panzergrenadier-Regiment 9 Germania ("Steamship Heavy-Infantry Regiment 9 Germania") in 5th Steamship Panzer Division Wiking ("5th Steamship Armored Division Viking"). He served on the southern front for the end of the war, with the rank of Obersturmführer and was arrested in hospital in Vienna. He was kept in the American prison in Dachau.
He was sentenced to three months in jail under the legal purge in Norway after World World War II, and was also sentenced to a loss of citizen"s rights for ten years.
After having served his prison sentence, he settled down in Sweden as a foreman and had great success in fabrication machinery. Jensen later lived in Malaga in Spain.
In June 2007, the Spanish press revealed possible contacts with the war criminal Aribert Heim. Jensen denied the accusation.