Three men suspected of funneling illegal guns to the streets of Philadelphia were arrested yesterday and charged with federal weapons-trafficking violations.

In announcing the indictment of the trio, U.S. Attorney Patrick L. Meehan said investigators were trying to trace the weapons they sold to an undercover agent back to their legal origins to determine whether they had been stolen or purchased for black-market sale.

The undercover agent purchased 22 guns - including 15 semiautomatic pistols - during the sting operation set up by a task force involving the federal Bureau of Alcohol, Tobacco and Firearms, Philadelphia police, and the state police. All but three of the guns had their serial numbers intact.

Handguns, particularly semiautomatics, have been used in 108 of the 128 homicides in the city this year through Tuesday.

Meehan and ATF and police brass announced the arrests at a news conference across the street from the John Paul Jones Junior High School in Port Richmond, in the shadow of which the sale of 18 of the weapons took place.

Because of that, Meehan said, the defendants face stiffer penalties if convicted.

Arrested without incident were Eugenio Santiago-Mejias, 47, of East Cambria Street; Jose Luis Guzman, 23, of East Orleans Street; and Jairo Correa Merejildo, 21, of East Lycoming Street.

Santiago-Mejias, also known as "Tito," faces a maximum sentence of 30 years to life behind bars if convicted because he is a felon, Meehan said. Guzman and Correa Merejildo, also known as "Cabeza," which means "head," each face up to 151/2 years in prison.

Officials did not know how many weapons the trio had sold on the streets of the city, but their arrests cut off one source, said Thomas Stankiewicz, special agent in charge of the ATF's Philadelphia office.

"These guys had no respect for the quality of life of the people living in the neighborhood," he said.

Johanna Foley, who lives near the school, said she could not believe gun-dealing was going on in her neighborhood.

Still, she said, crime and the sound of gunfire were common.

"My son is 15 years old and he's got to be in the house by 8:30 [p.m.]," she said. "It's bad."

Contact staff writer Joseph Gambardello at 215-854-2153 or jgambardello@phillynews.com.