After Ramsey County District Judge George Stephenson learned that a felon wanted for violating probation had threatened to kill him, he pulled the man's mug shots, studied them closely and then showed them to members of his family.

So when the man walked into Stephenson's 13th-floor courtroom Monday in the midst of a guilty plea, the judge recognized him instantly.

"I asked him to sit down, he walked out of the courtroom and I directed one of the deputies to bring him back inside," Stephenson said Tuesday, shortly after Peter Okezie Kalu was charged with making terroristic threats.

Kalu, 30, who was carrying a black bag but was unarmed, told investigators that he did not own a gun or have plans to get one, according to the complaint. When asked why he said he was going to kill the judge, Kalu said it was because the judge wanted to kill him.

In his bag was a typewritten statement that read in part: "Some idiot by the name of George T. Stephenson has signed out a warrant for my arrest. You have hurt me with no regards to my feelings. I will hurt you back. I will kill you. … I will gun you down in front of everybody before I turn myself [in] to the mental hospital."

Kalu, whose last address is unknown, was being held Tuesday night at the county jail. He was slated to make his first court appearance Wednesday on the charges.

The chain of events leading to Tuesday's charges began in February 2011, when Kalu pleaded guilty in Ramsey County District Court to mail theft. A state trooper who stopped him for speeding in St. Paul had found in his car nearly 200 pieces of mail addressed to residents and businesses in Brooklyn Park.

Kalu received three years probation and was told he would serve 15 months if he violated the terms of his probation, which included attending a cognitive skills course. The case was handled not by Stephenson but by another judge.

Last week, after failing to make contact with his probation officer, Kalu found out that a warrant had been issued for his arrest and that it had been signed by Stephenson. According to the complaint, Kalu told a probation official that he was going to find the judge online to see what he looked like and "kill him before police could catch me."

Kalu's probation officer told investigators that he also had recently threatened to kill a federal judge in Minneapolis for denying him benefits. He failed to appear in federal court last month on that matter.

When deputies brought Kalu back into the courtroom Monday, Stephenson said: "You are Mr. Kalu, right?" Kalu said yes, and the judge told deputies to take him into custody.

Stephenson, who has been on the bench for 12 years, said Tuesday that he did not know Kalu and had never seen him before. He said he had been threatened before, as many judges are, but that this was the first time that someone had sought him out.

The judge said he didn't fear a physical threat because Ramsey County screens for weapons at all courthouse entrances. But he admitted he was a bit unnerved by the letter in Kalu's bag, which repeated the phrase "I will kill you" several times.

"That was a little bit frightening," Stephenson said.