Two brothers from Mansfield and their sister in Dallas are charged in federal court with running a gang that trafficked in drugs and targeted other drug dealers for robbery.Cesar Ibarra, 39, and Hilberto Ibarra, 29, have been arrested. Their sister, Elva Sofia Ibarra, 36, had not been arrested as of Friday evening.Federal agents on Thursday searched a house in the 1600 block of Stratford Drive in Mansfield. An FBI spokeswoman said she could not discuss what they were looking for. Federal officials had no comment about whether the arrests and the Thursday searches were related.The Ibarras lead a gang called the Goon Squad, according to a news release from the U.S. attorney’s office. Ten members of the Goon Squad, most of whom live in Dallas, were in federal custody Friday and scheduled for detention hearings.The Ibarra siblings conspired with each other and others to traffic in drugs, commit robberies, burglaries and other acts of violence, the release said. Cesar and Hilberto Ibarra are accused of leading the Goon Squad. Other family members, including Cesar Ibarra Jr., were involved in cocaine, methamphetamine and marijuana trafficking, according to the release.Prosecutors say that the Goon Squad targeted individuals known or believed to be drug dealers for burglary, robbery or other acts of violence because they were likely to possess large quantities of illegal narcotics, cash or firearms and would not be likely to report offenses to authorities. The Goon Squad performed surveillance and reconnaissance on their potential victims, the release said. They also attempted to perform similar surveillance on members of law enforcement they believed were investigating their activities by taking photographs and recording vehicle-specific information, the release said. Mansfield residents said they noticed FBI agents at houses on Stratford and Fairfax drives early Thursday morning. “I can’t confirm the Fairfax address,” said Katie Chaumont of Dallas, the FBI spokeswoman. “That doesn’t mean we weren’t there. But I can confirm we were at the location on Stratford in Mansfield. It was law enforcement activity.”Residents said agents searched cars at the addresses. Chaumont said she could not say what FBI agents were looking for “because it is related to an ongoing investigation.” Amanda Rogers contributed to this report.