As if the potential links between Hasse and McLelland's shootings weren't enough, speculation has also extended to whether the shootings have any connection to the March 19 death of Colorado prisons chief Tom Clements, who was gunned down after answering the door to his house.
While authorities have offered no suggestion the crimes are linked, the man suspected of killing Clements was once a member of a white supremacist group, the 211 Crew. That man, Evan Ebel, died in a shootout with sheriff's deputies in northern Texas.
The white supremacist angle is just one of many possibilities, the Dallas Morning News quoted McLelland's former boss in the Dallas public defender's office as saying.
"It could be local meth lab people down there in Kaufman County, it could be Mexican cartel, it could be the Aryan Brotherhood," the newspaper quoted Former Dallas Chief Public Defender Brad Lollar as saying. "Or it could just be someone with a personal grudge."
On heightened alert
The federal Bureau of Alcohol, Tobacco, Firearms and Explosives joined Texas Rangers, the FBI and local authorities in investigating the killing of McLelland and his wife, the agency's Dallas office spokesman, Andrew Young, told CNN.
Several dozen FBI agents and support staff are now assisting the investigation, said Katherine Chaumont, a spokeswoman for the bureau's Dallas field office.
In Houston, Harris County Sheriff Adrian Garcia put District Attorney Mike Anderson and his family under 24-hour security, said Sara Marie Kinney, a spokeswoman for the prosecutor's office. Anderson's office was part of the same task force as Kaufman County authorities.
Mayor Fortner said Monday on CNN's Starting Point the fear is pervasive.
"I wonder if the governor is going to find anyone brave enough to take the job of district attorney," he said.