The man suspected of shooting an Idaho pastor six times over the weekend was arrested outside the White House Tuesday evening, authorities said. 

Kyle Odom, 30, was arrested by the Secret Service after he was seen throwing items over the White House fence. The Coeur d'Alene police department said the items included computer flash drives. 

Odom, a former Marine, is accused of shooting Pastor Tim Remington outside his church on Sunday, the day after Remington gave the invocation at a weekend campaign rally for Republican presidential candidate Ted Cruz. Authorities say there's no indication Remington's appearance with Cruz had anything to do with the shooting.

The Coeur d'Alene Police Department issued a warrant of attempted first-degree murder for Odom, who has no criminal record but does have a history of mental illness.

Earlier Tuesday, investigators said they had obtained a letter sent by Odom to his parents that also contained a flash drive. Documents on the drive indicated that Odom had targeted Remington and another parishioner at the Altar Church in Coeur d'Alene.

KXLY reported that Odom had claimed in a Facebook post hours before he was arrested that Remington was a Martian who had ruined his life.

Remington, 55, regained consciousness Monday night in a Coeur d'Alene hospital, said John Padula, the Alter Church's outreach pastor.

"He's whispering and talking to his family a little bit," Padula said Tuesday. "He's doing absolutely amazing. He gave me a thumb's up last night when I went in."

Remington, who is married and has four children, has no feeling in his right arm, Padula said.

Remington and his wife have been with The Altar Church for nearly two decades, and they have specialized in the treatment of drug and alcohol addiction, Padula said. The church has extensive programs, including in-patient rehabilitation, for addicts, Padula said.

Odom had no connection with the church before showing up before services early Sunday morning, Padula said. Coeur d'Alene Police Chief Lee White said Odom was armed while he attended services, and said that the violence could have been much worse.

Authorities said Odom waited for Remington outside the church after services, then shot him in the back as the pastor walked to his car. Police said Odom drove to the Spokane, Washington, area on Interstate 90 after the shooting, according to information from traffic cameras. He then turned south before they lost his trail.

Odom served in the Marines from 2006-2010, winning an Iraq Campaign Medal and other awards. He rose to the rank of corporal.

Odom later graduated from the University of Idaho with a degree in biochemistry.

Fox News Channel's Matt Dean and the Associated Press contributed to this report.