"Now I would like to get into the shop program so I can train for a job in construction," he said.
Diane Robinson said she has traveled to MCI from her home in Washington, D.C., to work with her son and offer him encouragement.
"I'm really proud of him," she said. "Everybody makes mistakes, but a parent must stand by a child."
In her address Tuesday to the 180-plus graduates, Diane Robinson acknowledged that getting a diploma or a certificate for vocational training is an important step toward self-sufficiency.
"You must learn to view this period in your life as just a temporary setback," she said.
Diane Robinson said that her son, for example, could have sat and complained, but he didn't.
"And you didn't either," she said, congratulating the 114 diploma recipients and the 71 who earned vocational certificates in sheet metal and upholstery.
MCI Principal Brad Keller said celebration of success is his favorite activity. He commended the students and his staff for their efforts.
Warden Lloyd "Pete" Waters said the proof of the value of education is in the number of inmates who don't return to prison.
"Without education, the majority of inmates do come back," he said. "Education is the first step to keep you out of here."
Inmate Raymond Perkins gave the student speech, encouraging his fellow prisoners not to reach his age - 50 - before they turn their lives around.
"Even though I wasted much of my life, I learned I still have value," Perkins said. "After all, up until now, our own thinking has only earned us a bed in this institution."
Perkins earned his diploma with academic honors.