Gov. Rick Perry named a longtime Tarrant County prosecutor to chair the governing board of the Office of Violent Sex Offender Management at a time when the agency has faced intense scrutiny.Christy Jack is a deputy chief for the Tarrant County district attorney’s office and has been on the board since Sept. 1, 2011. The office oversees the state’s civil commitment program for sex offenders.Jack replaces Dan Powers, who resigned as chairman this week, saying the workload is too heavy for a volunteer. Powers will remain a board member until his replacement is named, according to the governor’s office.Jack’s elevation comes as two other top officials are on leave after questions were raised about the agency’s operations.The Houston Chronicle reports that Executive Director Allison Taylor and program manager Deborah Morgan are on leave. Agency general counsel Celeste Blackburn confirmed that Taylor is on leave until Thursday. It’s unclear how long Morgan will be gone. Neither returned calls seeking comment.Kathy Walt, Perry’s chief of staff, said concerns have been raised about the agency’s secretive placement of violent sex offenders with little notification of community residents and legislative leaders. Walt said her office is “moving to address the leadership vacuum at this agency.” All high-risk sex offenders in the program have served prison sentences but are kept in custody under a civil commitment program because they are deemed too dangerous to return to society. About 350 offenders are being held in civil commitment, with roughly half in prison and the rest in halfway houses and jails.State Sen. John Whitmire, D-Houston, who chairs the Criminal Justice Committee, has asked the state auditor’s office and a state unit that prosecutes official-corruption cases to examine questionable contracts for housing offenders. “At an agency that deals with the worst of the worst, an agency that appears to have been out of control for some time with its bad decisions, having the top positions vacant or on leave is not in the public interest,” Whitmire said. The agency has been criticized for moving more than two dozen high-risk offenders into a north Houston boardinghouse with no notice to neighbors or lawmakers who represent the area, which is customary.After a public outcry, officials moved the offenders back to a minimum-security halfway house in east Harris County, which had demanded their removal because of security and operational concerns. Staff writer Mitch Mitchell contributed to this report, which includes material from The Associated Press.