Every week, Haerer tutors small groups of interested inmates at the Maryland Correctional Training Center and Maryland Correctional Institution, she said.
Regina Haerer "is loved for her devotion, enthusiasm and humility," inmate Douglas Scott Arey wrote when he nominated her for entry into the Hall of Fame.
She leads prayer groups, and teaches the rosary, Litany of the Hours and Psalms.
It's a job the lifelong Hagerstown resident never imagined she'd undertake. Haerer recalled riding past the "ominous" prison complex when she was a girl.
"I used to think I'd never go near those buildings," she said.
Decades later, she followed her faith and Sister Dolores Chepiga through the prison gates.
Haerer called her entry into Catholic teaching a fluke.
She was in the office of St. Joseph Catholic Church in Hagerstown when someone came in to donate a pile of books and magazines to inmates. Haerer commented that it might be interesting to work with the prisoners.
Several weeks later at Mass, Catholic nun Sister Dolores, who has been the Catholic chaplain at the prison complex for six years, asked Haerer to give the job a try.
It was almost five years ago when Haerer joined the other civilians who work at the prison complex.
"I've never felt intimidated," she said. "I feel infinitely safer there than on the streets."
Haerer said her work is rewarded by the inmates' appreciation for what she does, and she considers her pupils her friends.
She said she's constantly challenged by her students' curiosity.
"They ask a lot of questions," she said. "They tear the Bible sentences apart."
She's tutored one inmate for five years, and has taught between 16 and 20 other prisoners off and on over the years, Haerer said.
She said the men treat her with respect, consideration and kindness. Many of her Bible study students have become more open and trusting over time.
"I know people can change," Haerer said. "I've seen it."