Governors do not normally — if ever — have private visits with prisoners.

But one evening in September, Judith Clark, the former radical who drove a getaway car in the 1981 Brink’s armored car robbery that left three people dead, was summoned from a college program at the Bedford Hills women’s prison. She did not know who she would be seeing until she was brought into a room used for high school classes.

About 10 minutes later, Gov. Andrew M. Cuomo arrived.

As they sat down, he wanted to know first about her crime and her motivation.

“Were you on drugs?” Mr. Cuomo asked.

“No,” Ms. Clark replied. “I was on politics.”

Ms. Clark, now 67, had already served 35 years of a minimum 75-year term. She was not eligible to seek parole until 2056. Her only hope of getting out during her lifetime was a grant of clemency from the governor, a power Mr. Cuomo had almost never exercised in nearly six years in office.

The governor announced Friday that he was reducing Ms. Clark’s minimum sentence to 35 years, meaning not that she will be released, but that she will be eligible for parole in the first quarter of 2017.