One of the issues that disturbed Mr. Lawson in the 1970s was medical experiments, especially skin testing, then being done on prisoners at Holmesburg Prison.
In May 1974, he testified before a U.S. Senate committee on health chaired by Sen. Edward Kennedy. Mr. Lawson told the committee that the money prisoners earned from the drug companies made the risky skin patches they agreed to wear seem acceptable.
But the patches were later found to carry dangerous substances, and the inmates were never fully informed about the nature of the substances, he testified. Some developed painful scarring.
A self-described jailhouse lawyer, Mr. Lawson excelled at writing legal briefs and appeals for his fellow prisoners although he had no formal training.
Mr. Lawson's advocacy drew the attention of Allen M. Hornblum, the author of Acres of Skin: Human Experiments at Holmesburg Prison. Hornblum detailed Mr. Lawson's efforts to piece together a coalition of Quakers and civil rights advocacy groups outside the prison to lobby on behalf of the prisoners.
Mr. Lawson also testified in 1974 on behalf of Pennsylvania inmates whom he believed should be allowed to vote after they were released from prison. That right was finally granted in 2000.
"He was thrilled," said his daughter, Pamela Goodwin. "It gave him a lot of confidence to believe you can work through the system."
Informally known as "Lawson," he was born and raised in North Philadelphia, where he graduated from Simon Gratz High School.
He parlayed his love of photography into a skill, and created a silk-screen decal printing company called "Lean Machine Inc."
His silk-screened T-shirts carried positive messages such as "Save Our Children," "Each One Teach One," and "I Know I Am Somebody Because God Don't Make No Junk."
Later, Mr. Lawson worked at New Bethlehem Baptist Church as the building engineer until retiring in 2010.
Mr. Lawson was married to the former Vivian Mason for 41 years.
Surviving, in addition to his wife, is a son, Aquil Lawson; a daughter, Pamela Goodwin; a stepdaughter, Justine Mason; and a stepson, Graddie Ricks; two sisters; six grandchildren; four great-grandchildren; a niece; and three nephews.
A Janazah Prayer, or Islamic Service, will be held at 11 a.m. Wednesday, April 2, at Khadijah Alderman Funeral Service, 1924 W. Hunting Park Ave., Philadelphia. Interment is in Rolling Green Memorial Park, West Chester.