Two senior government attorneys with longtime experience in gangs have stepped in to handle a criminal case against 34 Aryan Brotherhood of Texas members after the previous lead prosecutor in Houston withdrew.

In an email to lawyers in the case, Assistant U.S. Attorney Jay Hileman, a veteran prosecutor of Aryan Brotherhood of Texas members, cited unspecified security concerns for his decision to withdraw from the case, according to Gus Saper of Houston’s Mallett Saper Berg, lead defense attorney for Aryan Brotherhood of Texas gang leader Terry Ross Blake.

"I don’t know what thought process went into him getting off the case," Saper said. "I think he did say something like some security concerns, but don’t know what they were."

Hileman’s departure, officially noted in court records on Wednesday, came after Kaufman County, Texas, District Attorney Mike McLelland and his wife were killed at their home on March 30. An assistant district attorney in Kaufman County, Texas, Mark Hasse, was killed outside the local courthouse on January 31.

Although no suspects have been named, investigators have honed in on the Aryan Brotherhood of Texas, who allegedly threatened law enforcement officials connected with a November racketeering indictment against 34 of its members. That case was brought by the U.S. attorney’s office in Houston, but Kaufman County prosecutors have been assisting.

Modeled after the Aryan Brotherhood, the prison gang founded in California’s prisons during the 1960s, the Texas group began focusing on white supremacy ideology and has expanded to include murder, robbery, assault and other crimes for profit.

"The case currently pending in the Southern District of Texas has been and will continue to be worked by the United States Attorney’s Office for the Southern District of Texas in partnership with the Department of Justice’s Criminal Division," office spokeswoman Angela Dodge said in a prepared statement. She declined to comment further. Hileman did not return a call for comment.

In Wednesday’s filing, U.S. Attorney Kenneth Magidson told U.S. District Judge Simeon "Sim" Lake in Houston that Tim Braley, deputy chief of the narcotics/organized crime drug enforcement task force, and Edward Gallagher, deputy chief of major offenders, were now the lead prosecutors on the case in Houston. The Justice Department’s David Karpel, a trial attorney in the gang unit in Washington, who has been involved in the case since indictments were handed down, remains lead counsel.

Justice Department spokesman Michael Passman did not respond to a call for comment. Braley and Gallagher did not return calls.

Braley was involved in an indictment last year against 25 alleged members and associates of the notorious Texas Mexican Mafia prison gang on drug trafficking charges. He also prosecuted recent cases against members of the Tri City Bomber Street gang and the 4th Street Bloods—both street gangs involved in drug trafficking.

Gallagher has focused on human trafficking, alien smugglers and gang cases. In 2002, he received the Director’s Award from then-Attorney General John Ashcroft for his prosecution of three international human smuggling groups. He received the same award in 2009 from Attorney General Eric Holder for his involvement in the Human Trafficking Rescue Alliance, over which he was named coordinator in 2004, in both training efforts and prosecution of cases.

Gallagher is an adjunct professor at the University of Houston Law Center, where he teaches human trafficking and national security law.

Hileman isn’t new to cases involving the Aryan Brotherhood of Texas, which was established during the 1980s in the Texas prison system. Several members recently had been sentenced as part of a case Hileman led,focused on the beating of a prospective member at the home of leader Steven Walter Cooke, also known as "Stainless," in Tomball, Texas. Of 12 defendants in that case, 11 pleaded guilty and the twelfth, David Harlow, of "Bam Bam," was found guilty last year.

In the recent case, two defendants—Ben Christian Dillon, also known as "Tuff," and James Marshall Meldrum, or "Dirty"—each pleaded guilty earlier this year to one count of conspiracy to participate in racketeering.

Saper said the recent case has always been directed from Washington. "Jay was local counsel assigned to help coordinate," Saper said. "He had responsibilities and if there was a hearing the Washington lawyer couldn’t be at, he would be responsible for being at court and handling day to day things."

As for Hileman’s replacements, Saper called them "excellent prosecutors." He said he has known both of them for 20 years.

He said the recent shootings haven’t been discussed in the courtroom, although few hearings have been held in the case. But he did have concerns of his own.

"I’m concerned about all the publicity," he said. "It’s certainly negative publicity—even the speculation. And that concerns me. If we have to go to trial and pick a jury, it can be a concern."

Contact Amanda Bronstad at abronstad@alm.com.