After the shooting incident took place, The Department of Justice released a press statement through its website. The press release credited the Kaufman Attorney's Office for helping them investigate two members of the Aryan Brotherhood of Texas.
The press release provides more info on the charges brought against the two gang members:
According to court documents, Dillon, Meldrum and other ABT gang members and associates, agreed to commit multiple acts of murder, robbery, arson, kidnapping and narcotics trafficking on behalf of the ABT gang. Dillon, Meldrum and numerous ABT gang members met on a regular basis at various locations throughout Texas to report on gang-related business, collect dues, commit disciplinary assaults against fellow gang members and discuss acts of violence against rival gang members, among other things.
Before the press release was issued, The Dallas Morning News noted that "authorities with knowledge of the assistant DA's caseload" said that Hasse was "heavily involved" in the Aryan Brotherhood case.
The press release released the name of the two Aryan Brotherhood members who pled guilty to their charges: Ben Christian Dillon, aka "Tuff", of Houston, and James Marshall Meldrum, aka "Dirty."
The shooting incident may have something to do with the case Hasse participated in. Fellow Aryan Brotherhood of Texas members may have sought retaliation in connection to the case.