Three defendants on Wednesday denied criminal responsibility in the death of a 66-year-old woman in a serial murder case in Amagasaki, Hyogo Prefecture, saying they were under the control of the alleged ringleader.

The three have been charged with confining and beating to death Kazuko Oe in 2011 on the orders of Miyoko Sumida, who killed herself at the age of 64 in a detention facility last December after her arrest on suspicion of having masterminded the grisly series of murders.

In Wednesday's hearing at the Kobe District Court, Oe's daughters Kae, 45, and Yumi, 42, and Yumi's former husband, Hiroyuki Kawamura, 43, admitted involvement in the woman's murder. But their defense lawyers insisted they had been under Sumida's absolute control and were thus not responsible for their actions. A ruling in their lay judge trial is due Oct. 31.