The victims of what became known as the Villa Salvarcar massacre were mainly teenagers at a birthday party in a working-class part of Ciudad Juarez, a violent city across the border from El Paso, Texas. At least eight others were wounded in the attack on Jan. 30, 2010.
The three judges will sentence Juan Alfredo Soto, Aldo Fabio Hernandez, Jose Dolores Arroyo and Heriberto Martinez on Monday. Prosecutors are seeking more than 100 years in prison each. Three suspects remain at large.
The conviction was reached at the end of an oral trial, which is rare in high-profile legal cases in Mexico, where most murder cases go unsolved.
Witnesses and relatives said armed men in two trucks blocked off a dead end street in Villas de Salvarcar, a neighborhood of modest cinderblock homes, and opened fire at three houses. They ended their rampage at a home where young people had been gathered for a party.
People who saw the gunmen open fire were initially afraid to testify and had to be convinced to do so by social workers.
The shooting sparked an outcry, with Ciudad Juarez's mayor saying the victims were "good kids" and the parents saying they had no ties to drug gangs.
Calderon visited Juarez days after the massacre to announce that he was increasing public funding in schools, hospitals and other social programs as part of a shift from a purely law-enforcement approach.
But drug violence continues to ravage Ciudad Juarez, considered the epicenter of Calderon's drug war. More than 3,100 people were killed in 2010 in the sprawling border city.
Gunbattles between security forces and criminal gangs take place often in violence-plagued regions of Mexico.
In the western state of Michoacan, federal police said late Thursday that presumed drug gang members shot at officers, who repelled the attack and killed four alleged criminals and wounded another in the city of Apatzingan.
Police said the gunmen were members of the Knights Templar, a criminal organization that split off from La Familia cartel, a cult-like drug gang.
After the confrontation, drug gang members set fire to trailers, buses, pickup trucks and other vehicles to block highways.
Associated Press writer Gustavo Ruiz in Morelia contributed to this report.
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