Mary Martha Costello, a longtime social services worker, dies

Mary Martha Costello, a former supervisor in the Child Protective Services Division of the Baltimore Department of Social Services, died of heart failure April 19 at the Barrington at High Oaks, an assisted living home in Richmond, Virginia. She was 82 and had lived in Towson and in Rocks in Harford County.

Born in Baltimore and raised on Melvin Avenue in Catonsville, she was the daughter of Peter Costello, a lithographer and a manager of the Inner Harbor’s old Federal Tin firm, and Mary Martha Heaps, a homemaker who was an editor of the University of Maryland’s Diamondback.


The family left Catonsville and moved to Jarrettsville. She was a 1958 graduate of North Harford High School and earned a bachelor’s degree in sociology at the University of Maryland, College Park.

Ms. Costello began a career in social work that spanned 50 years and included 36 years in social services for Baltimore Catholic Charities, Johns Hopkins Hospital, Kennedy Krieger Institute, Baltimore County Department of Social Services and Baltimore City Department of Social Services.


Along the way she received a master’s degree in social work from the University of Maryland, Baltimore, where she provided several chapters to textbooks on dealing with abused children. Ms. Costello maintained a private counseling practice in Baltimore and Harford County for two decades.

“She was sweet and demure as a young girl, but after going into social work she became a warrior,” said her brother, Christopher Costello. “When she got reports of abuse, she would go into public housing high-rises and take a kid out for protection. She had the air of a very determined woman. She had a lot of courage.”

Her brother also said: “She was determined to make things better. People she supervised appreciated how she stood behind them. During her years in social services, my sister worked to protect children from abuse and neglect. She advocated for changes in public policies that affected child protective services such as providing attorneys to represent abused children at custody proceedings. In later years she lobbied for better pay, resources and working conditions for social workers.”

Ms. Costello was proud of those she helped. She was friendly with Gilman School’s headmaster Redmond Finney, and introduced him to a bright and talented client whom she was able to guide. He graduated from Gilman, Princeton University and Harvard Law School.

“Mary Costello was a strong woman with a calm strength, courage, and quiet wisdom. I was blessed to have her enter my life when I was a small child who would soon be placed in a foster home in Sandtown/Winchester in West Baltimore,” said Keefe B. Clemons. “Mary was my case worker, and her care and determination helped transform my life. Mary not only approached Gilman School, which I was eventually admitted to and attended for twelve years. She initially drove me to and from the school to make sure I could take advantage of that opportunity.

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“As I moved on to college, graduate school, became a lawyer and beyond, Mary has been like a mother to me, providing me wise counsel, supporting me during challenging times and cheering my accomplishments. I was fortunate to have had her in my life for so many years. I have no doubt that she made a difference in the lives of countless others, but she will always have a special place in my heart.”

Her brother said Ms. Costello enjoyed her free time in Harford County.

“As a respite from the dealing with harsh realities of Child Protection Services, my sister enjoyed training horses and riding with friends along the abandoned Maryland & Pennsylvania Railroad right-of-way that her great-great-grandfather, John Hough Barnett, a civil engineer, helped construct.


Her extended family gathered at at her home in Street in Harford County for celebrations, holidays and picnics.

Ms. Costello moved to Richmond in 2012 where she loved to spend time at James River wetlands with her dog Sheila.

The family is planning to hold a memorial gathering in the Baltimore area this summer at a date and location to be determined.

Mary is survived by a brother, Christopher Costello of Columbia; six sisters, Patricia Duklewski of Towson, L. Clare Costello of Richmond Virginia, Laura L. Costello of Williamsburg, Virginia, Colleen Sorte of New York City, Julie B. Hipley of Catonsville and Therese K. Ziegler of Madison, New Jersey; and numerous nieces and nephews. Her twin brother, Peter E. Costello III, died in 2012. Another brother, David W. Costello, died in 2006.