Mary L. Johnson walked into her 90th birthday party Saturday with family and friends greeting and hugging her as Stevie Wonder’s rendition of the Happy Birthday song provided a soundtrack for the magical moment.

They came to celebrate the woman who spent much of her life trying to free people falsely accused of crimes they did not commit brought about by false confessions through torture by the Chicago Police Department. Johnson was one of the first people to file a complaint against the disgraced and convicted former Cmdr. Jon Burge, who led a torture ring for more than 20 years.

Her organizing has led to men being released from prison — and two of them showed up over the weekend for the party on the West Side.

Mark Clements and Gregory Banks said they owed their freedom to Johnson.

“It took the efforts of Mary L. Johnson and other mothers likewise who would come together. First of all, we were not believed as being tortured by Burge and his underlings. It took their voices. Without their voices, we would all still be incarcerated,” said Clements, who served 28 years in prison after being convicted of arson and murder when he was 16 in 1981.

Banks served seven years in prison after being falsely accused of armed robbery and murder when he was 20 in 1983.

“Mary is a pioneer. She’s given a lot to this movement. We give her all the respect that she’s supposed to get,” Banks said. “We love her, and we appreciate all that she has done.”

For Johnson, the occasion evoked happiness and sadness.

She was there without two of her four children.

Her son Michael Johnson, 69, is serving a life sentence in prison for kidnapping and murder – the very case that began her involvement to exonerate those falsely accused of crimes and to abolish the death penalty in Illinois.

And on Saturday morning, just hours before her celebration, her oldest son, Joe Johnson, 72 died unexpectedly from an unknown illness.

“I lost my oldest son today,” Johnson said through tears.

Still, Johnson expressed gratitude for those who attended the birthday party.

“I love it. I love these people. A lot of these people marched with me. And because of a lot of these people, we got the attention of other people,” Johnson said. “Every time someone is released from the prison system, I can celebrate.”

Johnson’s youngest child, Nina Johnson, said she was unsure her mother would make it to the party.

“My mother is amazing. She has four children, and each of us feel a favor from my mother. How she does it is a mystery to me,” Nina Johnson said.

Michael Johnson wrote a note for his mother from Western Illinois Correctional Center that was read at the party.

“Mama, every year and every chance I get, I try to tell you how much I love, honor, admire and respect you. I’ve always been in complete awe of you,” the letter said. “You taught me what love is and I saw what love looked like by watching you. For some reason, my eyes are filling with tears and I have this big lump in my throat. I love you, Sugar Lump.”

Reporter Michael Puente covers metro Chicago and Northwest Indiana for WBEZ. Follow him on Twitter @MikePuenteNews.