ST. JOSEPH, La. (AP) — A man who authorities said was mentally unstable and believed a device had been implanted in his head shot two hostages, killing one, at a rural Louisiana bank before state police shot and killed him.

The hours-long standoff began around 12:30 p.m. Tuesday when a gunman — identified by police as 20-year-old Fuaed (FOO-od) Abdo Ahmed — took two women and a man captive at Tensas State Bank branch in St. Joseph, which sits near Louisiana’s border with Mississippi.

Charla Ducote, spokeswoman for Rapides Regional Medical Center in Alexandria, La., said the wounded hostage, LaDean McDaniel, was in critical condition Wednesday morning. She could not provide further details.

Law enforcement officials have not identified the male victim, who was shot to death.

During hostage negotiations, authorities were able to get Ahmed on the phone with a friend in Alaska, Louisiana State Police superintendent Col. Mike Edmonson said. That was crucial in convincing Ahmed to eventually release a female hostage.

Ahmed had written a letter “detailing exactly what he was going to do,” Edmonson said.

“He was mad at people that he said were mean to him,” he said. “He had voices in his head.”

Edmonson said the man grew increasingly erratic as negotiations went on, sometimes hanging up on police. One of his demands to authorities was that they get the device out of his head, Edmonson said.

Eventually, Ahmed told negotiators he was going to kill the two remaining hostages. Edmonson said state police entered the building just before midnight Tuesday.

That’s when Ahmed shot the two hostages and then police shot and killed him, Edmonson said. Edmonson said both hostages were shot in the upper body. The second hostage who was shot was taken to a hospital in critical condition, but Edmonson said he did not have any other information on them.

A Gulfstream jet registered to the U.S. Department of Justice landed at the Natchez-Adams County Airport at approximately 8:30 p.m., presumably carrying federal agents responding to the standoff.

A Louisiana State Police helicopter also landed at the airport Tuesday evening. Adams County Sheriff’s Office officials escorted a group of cars from the airport across the Mississippi River Bridge.

The hostages were both shot with a handgun, but Edmonson said Ahmed was also armed with a rifle. He also had a duffel bag containing items he was going to use to torture the hostages.

“His intent was to inflict pain and kill these individuals,” Edmunson said.

But Edmonson said there was no indication Ahmed had any history with the hostages, who were bank employees, and authorities did not know why he picked the bank. The bank sits across the street from a service station owned by Ahmed’s family.

“These were good, God-fearing people,” he said of the hostages.

Edmonson said Ahmed’s parents were from Yemen, but he was a U.S. citizen and there was no indication that he had a political or religious motive.