Patrick Carr, 53, the son of an Irish bookie who became a mohawk-sporting sociologist known for his dry wit, his research on the corrosive mistrust between police and young people in high-poverty neighborhoods, and his love of the Philadelphia Union soccer team, died Thursday, April 16, after a near-decade-long fight with multiple myeloma, a blood cancer.

Mr. Carr taught sociology at Rutgers University. He was married to sociologist Maria Kefalas of St. Joseph’s University, an expert on family, poverty, and violence.

The couple, who lived in Bala Cynwyd with their three children, established the Calliope Joy Foundation, named for their daughter, 10, who suffers from a rare and untreatable genetic disease known as MLD (metatcromatic leukodystrophy). She’s lost the ability to see, walk, or talk.

Mr. Carr, who was diagnosed in 2011, had been told he’d live 10 years; Calliope, or Cal, has lived twice as long as doctors said she would.

That deficit for Mr. Carr arose "because Pat granted Cal all his miracles,” Kefalas said.

Quoted in a story on the front page of the New York Times last Monday, Kefalas linked her husband’s death to the coronavirus. She said that because of COVID-19, blood supplies in Philadelphia have been rationed and Mr. Carr couldn’t get enough of the transfusions he needed to battle anemia and to start a round of chemotherapy. “The pandemic expedited his death,” she said.

Born in Drogheda, Ireland, to a homemaker mother and a father who took bets for a living (it’s legal in Ireland), Mr. Carr earned bachelor’s and master’s degrees in sociology from University College Dublin. He got his Ph.D. from the University of Chicago, where he met Kefalas on their first day on campus in 1992.

“He had a mohawk, and he wore Dr. Martens [boots] and a Pixies T-shirt,” an alt-rock band from Boston, where Kefalas grew up, she said. “He was smart and quirky. And he was the only Irish vegetarian I knew.”

Within four months, they were engaged. “He made me believe I could do anything, a new feeling for me,” Kefalas said. “We became inseparable for 28 years.”

They moved to Iowa in the early 2000s to research the impact of educated young people leaving rural towns. Their 2009 book, Hollowing Out the Middle: The Rural Brain Drain and What It Means for America, helped make the couple stars in academia.

“That book is super-well-known,” said Laura Napolitano, sociologist at Rutgers University-Camden. Mr. Carr, who taught at St. Joseph’s for a while before switching to Rutgers in New Brunswick, was Napolitano’s mentor at St. Joseph’s.

Mr. Carr, along with Napolitano and a third scholar, wrote a 2007 paper, “We Never Call the Cops and Here’s Why.” It’s a study of young people in three unnamed high-crime Philadelphia Latino, African American, and white neighborhoods that shows they don’t hate the police, but that bad experiences make kids cynical.

Mr. Carr and Kefalas combined with St. Joseph’s sociologist Susan Clampet-Lundquist to write another influential paper, also in 2007, “The Sliding Scale of Snitching: A Qualitative Examination of Snitching in Three Philadelphia Communities.”

“They were living near us in Queen Village then,” Clampet-Lundquist said. “Pat became my oldest daughter’s first babysitter. He had a dry humor, and an intense desire to use his research to make things better. Also, we adored his zucchini-blueberry bread.”

Much of Mr. Carr’s work, which included the 2005 book Clean Streets: Controlling Crime, Maintaining Order and Building Community Activism, relates to a conundrum he harbored since he left Ireland, Kefalas said.

Drogheda was a rugged place, rife with violence and sick with drugs. “His getting out while others didn’t gave him survivor’s guilt,” Kefalas said. “It motivated his life as a scholar: Why are there kids lucky enough to leave, while others don’t?”

In 2014, Mr. Carr met with then-Mayor Michael Nutter, “pleading with him to end the stop-and-frisk program, which treated every Philadelphia kid like a criminal. He said we were poisoning good kids into hating police," Kefalas said. Mr. Carr’s entreaty went unheeded. But he continued talking to kids in the streets, this out-of-place, 6-foot, 200-pound Irishman who loved young people and hated the poverty they suffered.

Recently, he was researching a book on the perils facing witnesses to homicides.

Mr. Carr was a fan of the HBO show The Wire, and wanted to write a similarly styled account of witnesses in Philadelphia’s murder cases.

“Annoyingly good” at anything, in Kefalas’ words, Mr. Carr taught himself the mandolin, became an organic gardener, coached championship-winning kids’ soccer teams in Lower Merion, and originated a podcast of the Philadelphia Union in 2010.

With little use for priests or burials, Mr. Carr asked that he be cremated, with his ashes going to Kefalas and family in Ireland. He also wants his remains spread at Liverpool’s Anfield soccer stadium, and on a Colorado mountain where he almost died on a hike 30 years ago.

“I told him he could leave because we would be OK,” Kefalas wrote on Facebook. “He died an hour after.... I was lying.”

Along with his wife and daughter, Mr. Carr is survived by son P.J. and daughter Camille. No memorial arrangements have been made. The family requests that any donations go to the Calliope Joy Foundation.