An Italian man on trial for fraudulent bankruptcy opened fire in Milan's courthouse Thursday, killing his lawyer, a co-defendant and a judge before being captured nearly 25 kilometers away as he fled on a motorbike.

Premier Matteo Renzi promised a full-fledged investigation into how the gunman, Claudio Giardiello, managed to bring a gun into the fortress-like tribunal, where metal detectors are used for visitors but not for employees, magistrates and accredited lawyers. The suspect and two other men had been on trial for fraudulent bankruptcy.

When shots rang out in the courthouse, court employees barricaded themselves inside their offices and took cover under their desks while the gunman moved unimpeded from one floor to the next.

A lawyer in the building said there was "a lot of panic" at first. Later, after the gunman had fled the building, court employees and lawyers were eventually allowed to trickle out of the tribunal - women first, followed by the men, who had their ID cards checked.

Police arrested the suspect was caught by carabinieri police in Vimercate, near Monza, 25 kilometers from the scene of the shooting.

In addition to lawyer and co-defendant who were killed, authorities said the gunman shot a second co-defendant, seriously wounding him. Afterwards, he "walked through the building, going down a floor, and killed the judge,'' one official said.

Man Opens Fire at Milan Court, Killing 3, Including Judge