When Mary Clark was growing up in Beverly Hills, she led a fairly privileged life as the daughter of a wealthy merchant; actor Cary Grant was a neighbor. As an adult, she was married and a mother of seven. But in 1977, when her second marriage failed, Brenner longed for something more meaningful for her life. She had done charity work at a Mexican prison in Tijuana, and decided to chuck it all. She sold her belongings, became a Roman Catholic nun, and moved to the La Mesa Prison full time.
Why? “Something happened to me when I saw men behind bars,” during her charity visits, she said several years later. When back home in Beverly Hills, “I wondered if they had medicine and how their families were doing.” And when she moved there permanently, “I felt as if I’d come home.” She slept as the 8,000 inmates did: in a 10-by-10-foot cell. She ate the same food, and turned out each morning for roll call. The inmates — and the guards — called her Mama, but she was no pushover. “There isn’t anyone who hasn’t heard my lecture on victims,” she said. “They have to accept that they’re wrong. They have to see the consequences. They have to feel the agony.” But, she said, “I do love them dearly.” She didn’t just rely on prayer: she would personally step in to break up fights. She did leave the prison occasionally, though — to travel to Southern California to visit her children and 45 grandchildren, and to raise donations to fund her work. Her life was featured in a documentary in 2010: La Mama: An American Nun’s Life in a Mexican Prison. Sister Antonia died October 17, at 86.