Authorities on Monday said the man charged with murder in a Tennessee church shooting left a four-page letter that detailed his frustration at being unemployed, his hatred of gays and liberals, and his expectation that he would be killed by responding police.

Jim D. Adkisson, 58, has been charged with first-degree murder in the Sunday shooting at a Knoxville, Tenn., Unitarian church that left two people dead and five injured. Police said he acted alone.

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"It appears that what brought him to this horrible event was his lack of being able to obtain a job, his frustration over that, and his stated hatred for the liberal movement,” Knoxville Police Chief Sterling Owen IV said at a press conference Monday.

Adkisson is being held on $1 million bail, according to city spokesman Randy Kenner, who did not know if Adkisson had an attorney. He will appear at a preliminary hearing on Aug. 5.

Authorities said they are investigating the shooting as a possible hate crime.

"Anytime someone uses force to obstruct another person in the free exercise of their religious beliefs that is a violation of the federal civil rights statutes," FBI Agent Richard Lambert said Monday.

Police said Adkisson snuck a 12-gauge shotgun into the Tennessee Valley Unitarian Universalist Church in a guitar case Sunday morning and opened fire during a children's performance of "Annie." They recovered three spent rounds and more than 70 shotgun shells.

Adkisson, who told police he had no relatives, planned to be killed by police, Owen said.

"He indicated also in that letter that he expected to be in there shooting people until the police arrived and he fully expected to be killed by the responding police," he said.

But attendees were able to tackle him and hold him until police arrived.

Bill Haslem, the mayor of Knoxville, hailed the parishioners for their courage.

"It’s a tragedy for our city, particularly for this church congregation, but the way they reacted both in terms of supporting and in terms of subduing the shooter has really made a horrible situation better because it really could have been much worse," he told FOX News on Monday.

The two slain church members were identified as Greg McKendry and Linda Kraeger.

McKendry, 60, a burly usher "stood in the front of the gunman and took the blast to protect the rest of us," church member Barbara Kemper said.

Kraeger, 61, died at the University of Tennessee Medical Center a few hours after the shooting, Kenner said.

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No children were harmed. Members said they dove under pews or ran from the building when the shooting started.

Five of those injured were listed in critical or serious condition at a hospital Sunday. Two others were treated and released.

Kemper said the gunman shouted before he opened fire.

"It was hateful words. He was saying hateful things," she said, but refused to elaborate.

Owen said authorities believe the suspect had gone to the Unitarian church because of "some publicity in the recent past regarding its liberal stance on things."

The church β€” like many other Unitarian Universalist churches β€” promotes progressive social work, such as desegregation and fighting for the rights of women and gays. The Knoxville congregation has provided sanctuary for political refugees, fed the homeless and founded a chapter of the American Civil Liberties Union, according to its Web site.

Unitarians have roots in a movement that rejected Puritan orthodoxy in New England. Although the outlook and beliefs of individual Unitarian churches can vary dramatically, most congregations retain a deep commitment to social justice, which has led them to embrace liberal positions over the years. Unitarians were among the first to ordain women, support the civil rights movement and back gay rights.

Karen Massey, who lived two houses from Adkisson's home, told the Knoxville News Sentinel of a lengthy conversation she had with Adkisson a couple years ago after she told him her daughter had just graduated from Johnson Bible College. She said she ended up having to explain to him that she was a Christian.

"He almost turned angry," she told the newspaper. "He seemed to get angry at that. He said that everything in the Bible contradicts itself if you read it."

Massey said Adkisson talked frequently about his parents, who "made him go to church all his life ... He acted like he was forced to do that."

Police took statements from witnesses and collected video cameras from church members who recorded the performance.

Authorities also searched Adkisson's duplex in the Knoxville suburb of Powell on Sunday night. A bomb squad was called in as a precaution.

Police said they took the precautions because they had reports that Adkisson was a former member of the Army's 101st Airborne Division. They recovered a handgun at the residence as well as a letter from the state of Tennessee saying Adkisson's food stamps were going to be reduced, Owen said.

Neighbors described Adkisson as a friendly man who would often work on his motorcycle outside and go on long weekend rides.

But police said Monday that the letter left by Adkisson in his vehicle detailed his inability to find a mechanical engineering job, which he blamed on liberals and gays.

"He did express that frustration that the liberal movement was getting more jobs," Owen said.

Court records from neighboring Anderson County indicate Adkisson threatened violence against his spouse several years ago. In March 2000, his then-wife, Liza Alexander, obtained an order of protection against him after telling a judge that Adkisson had threatened "to blow my brains out and then blow his own brains out."

The shooting started as about 200 people watched 25 children perform a show based on the musical "Annie."

Church member Mark Harmon said he was in the first row.

"It had barely begun when there was an incredibly loud bang," he said.

Harmon said he thought the noise was part of the play, then he heard a second loud bang. As he dove for cover, he realized a woman behind him was bleeding. She looked like she was in shock, touching her wound, he said.

"It seems so unreal," Harmon said. "You're sitting in church, you're watching a children's performance of a play and suddenly you hear a bang."

Harmon said church members just behind him in the second and third rows were shot. His wife told him she saw the gunman pull the shotgun out of the guitar case.

FOXNews.com's Sara Bonisteel and The Associated Press contributed to this report.