USULUTAN, El Salvador -- Police say an angry mother-in-law was behind the slaying of a popular US union leader who was shot in the back days before he was to meet with members of Central America's growing labor movement.
But Gilberto Soto's family, international activists, and the country's human rights ombudswoman have questioned the arrests made so far, saying police need to pursue whether the US Teamster's killing was politically motivated.
Human rights ombudswoman Beatrice Alamanni de Carrillo said Monday the suspects showed signs of torture and sexual abuse. She criticized police for basing most of their case on unidentified sources.
''The results are extremely worrisome . . . because there are serious irregularities and violations of judicial guarantees," she said. Police denied it.
Soto, a US citizen born in El Salvador, flew to Central America on Oct. 30 to support truck drivers and port workers trying to organize in El Salvador, Nicaragua, and Honduras.
But he never got a chance to hold any meetings. After a week of vacation, he was gunned down Nov. 5 while talking on his cellphone in front of his mother's house in Usulutan, 70 miles southeast of San Salvador.
Police say Soto's mother-in-law, angry about an undisclosed family dispute, hired several hitmen to kill the 49-year-old Teamster from Cliffside Park, N.J. Six people -- including the mother-in-law, Rosa Elba Ortiz, and two protected witnesses -- were taken into custody.
Soto's brother, Francisco Soto, acknowledges his brother had a rocky relationship with his wife, Elba Maritza Ortiz. Soto's sister, Arely Soto de Chacon, said the two had agreed to split once the wife's US residency papers were settled.
But no one in the family believes his wife's mother hired a killer.
Activists took out ads last week in Salvadoran newspapers demanding an independent commission investigate the death and condemning the November robbery of the offices of El Salvador's Center for Labor Studies and Support, a group that reports labor rights abuses.
Gilberto Garcia, the center's vice president and one of Soto's main contacts, said the center lost all its equipment and files, which included information on who was trying to organize unions in El Salvador, a country where less than 5 percent of workers are union members.
''It was just too much of a coincidence," he said. There have been no arrests in the break-in.
Teamsters President James P. Hoffa has asked Secretary of State Colin Powell to pressure El Salvador to investigate Soto's death, and the union rallied scores of US congressional members to sign a letter to the State Department.
National Police Director Ricardo Meneses said officers are confident Rosa Elba Ortiz was behind the killing. But investigators have six months before the case goes to trial and Meneses says officials are still following every lead.
At the request of El Salvador's government, the FBI has begun questioning friends, family members, and co-workers in the United States about any of Soto's possible enemies.
Soto's wife has moved out of the New Jersey apartment she shared with her husband, saying she was afraid to stay, according to Francisco Soto, who lives in North Carolina. She has stopped answering her phone and was not available for an interview.
Gilberto Soto, who emigrated to the United States in 1975, was trying to help rebuild Central American unions devastated by years of civil war and faced with governments that still associate union members with the region's bloody leftist uprisings of the 1970s and 1980s.
Recent developments had made Soto's trip even more important. Central America is in the process of forming a customs union from Guatemala to Nicaragua, effectively opening borders within the region and allowing the relatively free movement of people and goods. Soto was looking into uniting the region's unions, as well.
Labor leaders also have been working to sink the proposed Central American Free Trade Agreement with the United States, arguing it doesn't protect workers. The pact, which must be approved by the US and Central American congresses, could bring even more work ferrying cloth and finished textiles to and from the region's factories.
Gilberto Soto, a successful organizer working to bring together independent truckers in New Jersey, was sent by the Teamsters to check on progress and see if the union could provide support.
His slaying has put a spotlight on workers' rights, and the Teamsters have asked US Trade Representative Robert Zoellick to remove El Salvador, whose government is the only one in Latin America still sending troops to Iraq, from a list of developing countries receiving preferential treatment.
''It took what happened to Gilberto to get people to open their eyes," Garcia said.