Also involved in the murder were Stjepan Javor, Matija Soldin, Zvonimir Pospišil, and Mijo Babić.
Hranilović was implicated in the murder after the arrest of Stjepan Javor, head of the HPO, on 31 October 1929.
The HPO was accused of being a terrorist organization and Hranilović was charged with the murder of journalist Šlegel, along with Javor and Soldin.
During the trial, the HPO was accused of associating with the nationalist exiles Ante Pavelić and Gustav Perčec.
He sparred with the court several times, including one instance where he called himself a "citizen of imprisoned Croatia".