Bentley, 74, was booked into a Montgomery County Jail Monday on charges of failing to file a major contribution report and knowingly converting campaign contributions to personal use, according to booking information on the Montgomery County Sheriff's Office website.
When asked if he was guilty at the Montgomery County Courthouse, Bentley responded, "Yes, sir."
Bentley signed a plea deal that requires him to reimburse the nearly $9,000 his campaign spent on the legal fees of former aide Rebekah Mason, with whom he is accused of having an affair. In addition, he must forfeit all the money in his campaign account -- which is in excess of $36,000 -- to the state.
The former governor will also be required to complete 100 hours of community service as a physician.
As part of the plea deal, Bentley also agrees to not pursue elected office in the future. He must waive any retirement and other benefits to which he would otherwise be entitled as well.
During the announcement that he was resigning, Bentley said he received the "greatest honor" of his life when he was elected as governor of Alabama and apologized for letting the people of Alabama down.
"I want you to know, I love our people with all my heart, and I want nothing more than to serve them," he said. "The time has come for me to look at new ways to serve the great people of our great state. I have decided it is time for me to step down as Alabama's governor."
Bentley's last words as governor were: "So, thank you. Goodbye, and I love this state -- from the bottom of my heart."
Alabama lawmakers began impeachment hearings on Monday for the Republican governor, whose alleged indiscretions with Mason were detailed in a report by Jack Sharman, a veteran Birmingham-based lawyer.
"Governor Bentley directed law enforcement to advance his personal interests and, in a process characterized by increasing obsession and paranoia, subjected career law enforcement officers to tasks intended to protect his reputation," the report states.
Lt. Gov. Kay Ivey will replace Bentley as governor.
Although details of about the alleged affair have been circulating for over a year, the report, which was issued by the House Judiciary Committee of the Alabama House of Representatives, offers a more complete window into the alleged affair than had been previously rendered.
For example, the report states that Bentley sent his wife, Dianne, a text message that read "I love you Rebekah."
The alleged text was accompanied by a red rose emoji, according to the report.
GQ magazine reported that in 2014, Bentley's wife surreptitiously recorded him speaking to Mason on the phone in an intimate manner.
According to GQ's reporting, the text message with the rose emoji was sent a few weeks after the recording was made.
Dianne filed for divorce in 2015, according to the Montgomery Advertiser.
In a press conference last December, Bentley admitted making sexual comments to Mason and apologized to Alabama residents, but denied having an affair.
"Since that time I have apologized to members of my family, to Mrs. Mason and her family and I apologized then for any conversations and behavior then that was inappropriate," Bentley said, referring to allegations about his affair. "Today I want to apologize to the people of the state of Alabama and once again I want to apologize to my family. I am truly sorry and I accept full responsibility."
Bentley also denied doing anything that would warrant his removal at that time.
"I want everyone to know though that I have never had a physical affair with Mrs. Mason," he said. "I can assure the people of Alabama I have never done anything illegal. I have never asked any member of my staff or any cabinet member to lie."
Mason, for her part, resigned from her post in March of 2016, which was announced through a statement issued by Bentley's press office. "I have resigned as Senior Political Advisor to Governor Bentley and will no longer be paid from his campaign fund," the statement said.
"My only plans are to focus my full attention on my precious children and my husband who I love dearly," it continued. "They are the most important people in my life. Thank you for your prayers for our family."
Jon Mason, her husband, who, according to ABC affiliate WBMA, works as the director of the Governor’s Office of Faith-based and Volunteer Service, released a statement about the allegations on his Facebook page.
“I wanted to share that I long ago resolved the personal issue playing out now for everyone this week. Please continue to support families, the governor, and our state with prayers as we all move forward,” he wrote.
Jon Mason also referred to his wife a “child of God.”
The report also alleges other potentially embarrassing details, including an incident that occurred during a 2014 trip to Washington, D.C., in which the septuagenarian apparently opened the hotel room door while wearing only his boxer shorts, expecting Mason to be on the other side of it.
Bentley's alleged affair with Rebekah Mason also became apparent to members of his staff and he started calling his Mason "baby" during meetings.
"Over time, the nature of the Bentley-Mason relationship also became more obvious to the Governor’s staff," the report said. "Zach Lee reported to Heather Hannah during the re-election campaign that Governor Bentley had begun to call Rebekah Mason 'baby' in meetings and that Governor Bentley and Mason frequently went to lunch together by themselves."
Zach Lee is Alabama's director of Federal & Local Government Affairs, according to a government website.