In November 1943, after the assassination of the Federal Secretary of the Fascist Party of Ferrara, Igino Ghisellini, Vezzalini led the "punitive expedition" that resulted in the execution of eleven anti-Fascists and Jews at the Castello Estense.

He was later appointed prefect of Ferrara, leading the crackdown on the local Resistance with the help of the "Giorgi" Company (a special unit of the Republican National Guard), also known as the "Tupin", which soon became known for its tortures, extrajudicial killings and theft from Jews and suspect anti-Fascists.

[1][2][3][4] He was one of the judges of the Special Tribunal for the Defense of the State during the Verona trial, which tried the members of the Grand Council of Fascism who had voted a motion of no confidence against Benito Mussolini on 25 July 1943.

[1][3][4][5][6] From 22 July 1944 to 15 January 1945 Vezzalini was prefect of Novara; there he directed operations against the partisans, especially in the Ossola Valley, and there he was reached by the "Tupins", commanded by Captain Carlo Tortonesi, which effectively became his bodyguard.

After being dismissed from his post as prefect in January 1945, he went to Bologna, but was expelled by the local German command, which accused him of sowing panic among the population with the atrocities committed by his men; he then moved to Modena and later to Genoa, where he was appointed Inspector of the Republican Fascist Party.