May 30 (UPI) -- The man who shot and killed two police officers and a civilian in Liège, Belgium, killed a fourth person just hours before the attack, Brussels' interior minister said.
Gunman Benjamin Herman bludgeoned to death a prison cellmate with a blunt object at his home just hours before Tuesday's stabbing and shooting two police officers and a bystander, Interior Minister Jan Jambon said.
Herman fled from the scene and took a cleaning woman hostage at a nearby high school, authorities said. Two police officers were injured in a shootout there and Herman was killed. The hostage was not harmed.
The dead officers were identified as Lucile Garcia, 45, and Soraya Belkacemi, 53.
Jambon said there are signs Herman was "radicalized" in prison and prosecutors said they're treating the attacks as terrorism.
"It could have been because he had nothing to look forward to, because he also killed someone the night before, the guy's psychology and the fact... he may have been on drugs," Jambon said.
Herman, 31, was released from jail Monday, where he had been serving time for theft and drug offenses, when the standoff in the town of Liège began.
Jambon said the incident was an "isolated case."
"He wasn't part of a network, he did not receive instructions from anyone else, so there is no need to raise the terror threat alert level," he said,
Herman's goal was to attack police, police chief Christian Beaupre said.