But even more important was that the Santiago case was one of those that finally persuaded ATF brass in Washington to let the bureau investigate arson cases.
With the nation's first arson task force, Philadelphia became a model for the rest of the country.
Walter Wasyluk, who spent 25 years as an ATF agent and served as a Philadelphia police officer, New Jersey state trooper and a Marine, died Sept. 2 of lung cancer. He was 71 and lived in Pennsauken.
When ATF higher-ups balked at arson investigations, Wasyluk had a simple argument: The Moltov cocktail was listed as a firearm under ATF definition, but other forms of arson were not.
"What I presented was, what the hell's the difference if I make a Molotov cocktail, or I take gasoline and pour it on the floor and get a pack of matches and torch the place?" Wasyluk told the Inquirer in 2009.
The logic eventually sank in.
"The Santiago case was his proudest thing," said his nephew James Papaycik, a retired Atlantic City cop. "It was a real feather in his cap. He got an innocent man off."
The family of Radames Santiago, who was Puerto Rican, stirred racial tension in their predominantly white Feltonville neighborhood. Someone threw a Molotov cocktail into their rowhouse the night of Oct. 5, 1975, killing Santiago's wife, Ramona, and four children. Radames was badly burned, but survived.
Police arrested Robert "Reds" Wilkinson, who was seen nearby, and cops beat a confession out of him. He spent 15 months in prison before his conviction was thrown out, and six homicide detectives were sent to prison for police brutality.
Walt led the federal probe that exonerated Wilkinson. Two neighbors, Ronald Hanley and David McGinnis, admitted that they carried out the firebombing and that Wilkinson wasn't involved.
Walt was also involved in the investigation of MOVE, and his work led to the interruption of a possible bomb plot by the back-to-nature cult and the arrest of its leader, Vincent Leaphart, known as John Africa.
Leaphart was acquitted but died in the fire that resulted from a police bombing of the cult's headquarters, at 6221 Osage Ave., in West Philadelphia, in May 1985. Five other adults and five children also died.
"He was a superagent," said a former partner. "He made a lot of big cases but was very low-key, very unassuming."
"He would give you the shirt off his back," said his daughter, Diane Marie Iardella, an ATF agent in Delaware. "He was very blunt in his opinions; you always knew where he was coming from."
Walt was born in Philly and grew up in Northern Liberties. His father, Wasyl Wasyluk, was a native of Ukraine. His mother was the former Tekla Watras.
He attended Roman Catholic High School and Dobbins Technical-Vocational High. He joined the Marines at age 17 and served in Japan. He later became a staff sergeant in the Army Reserves.
He joined the Philadelphia Police Department in 1963 and became a New Jersey state trooper in 1965.
Walt and his nephew visited Ukraine, where family members still live. They were farm workers, and Walt bought one family a horse and some pigs.
He married the former Judith Gordon in 1963. She died July 5, 2008, at age 66.
Besides his daughter, he is survived by a son, Michael Wasyluk; a sister, Mary Ann Bramlage; and two grandchildren.
Services: Mass of Christian Burial 10 a.m. Friday at St. Peter Church, 43 W. Maple Ave., Merchantville, N.J. Friends may call at 7 p.m. Thursday at the Murray-Paradee Funeral Home, 601 W. Route 70, Cherry Hill, and at 8:30 a.m. at the funeral home. A Parastas service will be held at 8 p.m. Thursday at the funeral home. Burial will be in Locustwood Memorial Park, Cherry Hill.
In lieu of flowers, donations may be made to the Ukrainian Catholic Cathedral of Immaculate Conception, 833 N. Franklin St., Philadelphia, or St. Peter Church.
Contact John F. Morrison at firstname.lastname@example.org or 215-854-5573