A rogue pilot who allegedly stole an aircraft and threatened to crash it into a Mississippi Walmart on Saturday has been arrested, according to Tupelo, Mississippi, police chief John Quaka.

Driving the news: The pilot, identified as Cory Wayne Patterson, is expected to face charges of grand larceny and making terroristic threats. The federal government may proceed with further charges, police said.

• Patterson landed the plane in an open field after flying for nearly four hours on Saturday, authorities said. He remains in custody.
• "He will get the help he needs as far as whatever he's dealing with," Tupelo mayor Todd Jordan said at a news conference.

What we know

The pilot stole a Beechcraft King Air twin-engine aircraft from the Tupelo Airport early Saturday morning, Quaka said.

• Patterson, who is an employee of Tupelo Aviation, had access to the aircraft and likely fueled it up Friday night, the police chief said.
• At about 5:20am, Patterson reportedly called 911 and said he was going to crash his plane into a Walmart in Tupelo. The Walmart was promptly evacuated.

Negotiators spoke with Patterson, who told police he did not know how to land the plane, so a separate pilot helped out.

• The pilot has some flight instructions, but he is not a licensed pilot, Quaka said.

Patterson allegedly posted a message on Facebook while flying the plane "that in essence said goodbye," Quaka said.

• At 10:12am, a negotiator reestablished contact with the pilot, who confirmed that the plane had landed.

The plan did suffer damage, but no one was injured, Quaka said.

The pilot's family members said they "were very concerned" and "very thankful that no harm was done," Quaka said.

What we don't know

The pilot's motivation for the incident remains unclear.

• "We will run down with the motivation," Quaka said at the news conference. "We will pursue any angle and avenue that there is. We will work in conjunction with the FBI to do so."

The pilot's fuel situation before landing the plane wasn't clear, either. But Quaka said police had "reason to believe that he was very close to running out of fuel."

What's next: The FBI will be "assisting our state and local partners" with the investigation, Jackson FBI acting public affairs officer Katie Greenleaf said in a statement emailed to Axios.

• "This is an ongoing investigation and I will be releasing more information as I am able," she said.

Go deeper: Police: Rogue plane lands, pilot in custody after threatening to hit Mississippi Walmart