KIEV, Ukraine — The murder trial in Nikopol, a town in eastern Ukraine, was entangled in bureaucratic delays that were clearly angering a father of one of the victims.

By the time a hearing opened on Nov. 30, the judge had already delayed the case 20 times over a year and a half. Two weeks earlier, the father, Ruslan Tapayev, had posted on Facebook that “the criminals who committed the crime should be punished. Otherwise, society will plunge into chaos.”

When the 21st hearing led to yet another postponement, the distraught man decided to take justice into his own hands. He pulled the pins from two hand grenades, then threw one at the three defendants and held the second, killing himself.

“It blew the windows out, and there was a fire, screaming and panic,” said Anzhelika Bahrova, a judge who just moments before had stepped out of the courtroom. “It is not easy to forget. Still, everything here reminds me of that blast.” One of the defendants was killed, and a dozen others were wounded.