Christopher D. Warren, 58, a prominent and sometimes mouthy Philadelphia defense lawyer who made his name representing mobsters and gangsters, was found dead by his landlord on Saturday, Sept. 8, in his North Carolina home.

The official cause of death was an aneurysm, said Laura Feldman, Mr. Warren's ex-wife. Feldman said a memorial service will be held in December because "his friends are from all over the country, and they all want to come."

After defending Angelo "Fat Ange" Lutz, who spent seven years in federal prison as a "mob associate" convicted in 2001 of bookmaking and racketeering, Mr. Warren became one of Philadelphia's preeminent criminal defense attorneys.

His mob clients included George "Georgie Boy" Borgesi and Joseph "Scoops" Licata. Recently he had been a defense lawyer for the  rapper Meek Mill. He specialized in criminal defense in state and federal courts.

Eddie Jacobs, the longtime attorney for some of Philadelphia's most prominent mobsters, worked many cases with Mr. Warren. He called him "just one hell of a guy."

"I'm going to miss him personally, I'm going to miss him professionally," Jacobs said. "He had a lot of talent in that 5-foot, 7-inch frame. What he lacked in stature, he made up in intellect and hard work."

Mr. Warren retired last November to the Outer Banks. One of his last clients was former Democratic State Rep. Leslie Acosta, who pleaded guilty in 2016 in a money-laundering scheme.

"He wanted to retire early, and he did, and he got to enjoy it for eight or nine months," Jacobs said. "We talked every few days. He was in good spirits."

His body, which was not discovered for several days, was found in Salvo, an unincorporated community on Hatteras Island.

Feldman said Mr. Warren had "a brilliant legal mind. He overcame great obstacles in his life, and that's what sticks out to me."

Mr. Warren, whose father died when he was young, was a native of El Paso, Texas.

He dropped out of high school three times, but after earning his GED he attended Cooke County College and then North Texas State University (now the University of North Texas). He earned his law degree at St. Mary's University in San Antonio. Feldman and Mr. Warren met when they attended law school and moved to Philadelphia shortly after passing the bar exams in 1987.

He was known as a hard drinker and a heavy smoker.

Dennis J. Cogan, a close friend and lead defense attorney in the corruption trial of former State Sen. Vincent J. Fumo, recalled that in 2008 he tried to enlist Mr. Warren's assistance. But he said Mr. Warren "was suddenly hospitalized with a serious heart problem. So for a good 10 years he's been fighting health problems without taking care of himself."

Cogan called him a "brilliant lawyer with a kind heart."

"It's really hard to imagine anybody smarter than him who has practiced criminal law in this city that I have come across," he said.

In addition to his former wife, Mr. Warren is survived by a son, Jake, and a grandchild.