Mercep, currently kept in the prison infirmary, has suffered several strokes and attends his court hearings in the company of a doctor.
One of the witnesses at today's hearing was a former interior minister, Zeljko Tomljenovic, who said that everyone, including the then state leadership, had known about the crimes in Pakracka Poljana and the existence of the unit led by Tomislav Mercep.
Although the witness said he had no knowledge that Mercep had been the official commander of the unit, he knew that the unit used to gather at the Zagreb Trade Fair Centre and in the Pakrac area.
He said that he did not know under which circumstances Mercep had been employed in the Ministry of the Interior, and added that the ministry employees had not been glad to have Mercep with them because he was damaging the ministry's reputation.
According to Tomljanovic, the unit that committed crimes against dozens of Serbs was established after Mercep arrived from Vukovar and that it did not receive its equipment and supplies from the ministry.
Josip Manolic, the head of the Office for the Protection of Constitutional order in 1991, was to have testified today, but he will take the witness stand on 19 June.