UPDATED — 2:41 p.m.

For more than two decades as Maryland’s prison librarian, Glennor Shirley has connected inmates to the world beyond bars using books. She stocked their tiny libraries with biographies of great Americans, redemptive novels about street life, math textbooks, encyclopedias, illustrated books about snakes, and even Jackie Collins romance novels.

Her motivation for helping convicted murderers, rapists and armed robbers has always been simple: She believes reading is a fundamental right that can soften and enlighten the hardest of souls.

“I am basically a person who believes in justice and what is right,” she told me earlier this year, for a profile that generated hundreds of supportive e-mails and several thousand donated books.

Today is her last day on the job.

Miss Shirley, as she is known to prisoners, is retiring. She is too polite and sweet-tempered to say so herself, but her counterparts in other prison library systems have said that Maryland’s inmate reading program -- widely admired and imitated around the country -- has been decimated by budget shortfalls. Staffing is down. Funds are tight.

“I thought this was the right time to make a move,” Miss Shirley told me Thursday night. “I was really not being as effective as I want to be in the position I had.”

Though prison libraries aren’t going away, Miss Shirley’s departure is likely to disappoint and frustrate the thousands of inmates who had come to rely on her advocacy for education and reading. She was often asked why taxpayer money should be used to make a prisoner’s life more rewarding. Her standard answer: She wants to help them become taxpayers again. Without an education, she’d say, that’s impossible.

“I can tell you that among inmates and staff alike, Glennor is a beloved and highly respected figure,” said Mark Vernarelli, a spokesman for Maryland’s correctional department. “She considers education and reading to be key elements in life changes behind bars. And most importantly, she treats everyone as an important person. She will be sorely missed.”

Miss Shirley’s long career in prisons was essentially a happy accident. She immigrated to Maryland in the 1980s from Jamaica, where she was a librarian. While working low-level jobs in public libraries during the day, she worked nights in a prison library to pay her bills.

“I needed the money,” Miss Shirley told me.

The first time the prison gate closed behind her, “I had hundreds of inmates in my face,” she recalls. “It was a strange feeling, these dozens of eyes looking at you and assessing you.”

Eventually prisons became almost a second home. Miss Shirley started innovative programs, including one for prisoners to read to their children during visiting hours. She sent inmates to their cells with children’s books to rehearse so they wouldn’t be nervous. On her blog about life behind bars, she quoted an inmate on his feelings when reading to his children: “It couldn’t get any righter.”

Lucy Holman, the president of the Maryland Library Association, said Miss Shirley, a past president of the group, “truly believed in serving this population. She did it with tenacity and perseverance.” Holman added: “While we hope she will still remain active in the library community, I think it is a great loss for the state and for prison libraries particularly.”

Miss Shirley plans on taking some time off, then continuing her advocacy for prisoners. She wants to help inmates become comfortable using public libraries after their release. “In prison they use the library a lot,” she said. “They don’t use libraries so much when they get out. They seem intimidated. Many of them have never used computers or the Internet before, so they don’t want to look foolish. I want to help with that.”

She has been saying her goodbyes this week. She got a card from some inmates that read: “With deepest thanks and gratitude on your retirement from decades of advocacy on behalf of tens of thousands of Maryland prisoners. We will forever miss your enthusiasm of library services and especially your gorgeous smile.”

Prisoners are not supposed to touch employees. There are strict rules. But the other day, when she told an inmate she was leaving, he said, “I don’t care if I get in trouble, Miss Shirley, I’m gonna have to hug you.”

He did.

“That was very emotional for me,” Miss Shirley said. “I had to get out of the prison quickly.”