KAUFMAN COUNTY, Texas (CNN) -- Frayed nerves and a palpable tension cloak this quiet Texas county where the FBI, the Texas Rangers and half a dozen other agencies are on the hunt for the killer or killers bent on taking out top criminal justice officials.
Kaufman County District Attorney Mike McLelland and his wife, Cynthia, were found dead in their house Saturday, two months after an assistant district attorney was gunned down in broad daylight outside the county courthouse.
The killings have residents and prosecutors in Kaufman, east of Dallas, on edge -- and on guard.
Are the deaths connected? Are they the work of a lone wolf? Are they retribution?
Most troubling, will there be more?
"I think we take for granted a lot of things," resident Jim Norbeck told CNN affiliate WFAA. "And when they hit close to home, the awareness really goes up."
Kaufman County Judge Bruce Wood told CNN that the deaths have been "a major traumatic event."
"The folks who work in the courthouse, they've been through a lot," he said. "I've been trying to think of the right words to describe what we're going through. It's shock and disbelief."
Wood believes there is a "strong connection" between the McLellands' deaths and the slaying of Assistant District Attorney Mark Hasse, who was killed January 31.
The two prosecutors "worked on similar cases very closely," said Wood, the county's top elected official.
"Hasse's murder was a complete shock, and now this. This is not the way our society is supposed to function," Wood said.
Investigators at the McLellands' home recovered several shell casings from a .223-caliber rifle, a law enforcement source told CNN Sunday.
Exactly who fired them, and why, remains uncertain.
The Kaufman County sheriff's office won't officially say whether the killings are connected.
But some speculate whether the Aryan Brotherhood may have played a role.
McLelland himself, in an interview with the Associated Press, had raised the possibility that Hasse was killed by the white supremacist gang.
"We put some real dents in the Aryan Brotherhood around here in the past year," McLelland told the agency.
He said Hasse had not prosecuted cases against such gangs, but his office handled several.
In November, a federal grand jury in Houston indicted 34 alleged members of the Aryan Brotherhood of Texas -- including four of its senior leaders -- on rackettering charges. Multiple agencies investigated the case, including officials from the Kaufman County District Attorney's Office.
Weeks later, the Texas Department of Public Safety issued a statewide warning saying it had "credible information" that members of the Aryan Brotherhood were planning to retaliate against law enforcement officials who went after the gang's leadership.
In the same interview, McLelland told the Associated Press that he began carrying a gun after Hasse's death and was answering his door more carefully.
County officials 'on edge'
On Monday, the Kaufman County courthouse will reopen for the first time since losing its top prosecutor.
But the district attorney's office will remain closed.
The tragedy is too raw, and the future is still uncertain.
"We are taking precautions to protect other elected officials in the county," county Sheriff David Byrnes told reporters Sunday. He declined to say what those measures were.
Mayor Fortner said he hoped the killer or killers are caught "before any more people are lost."
The county judge said McLelland never told him he was worried, even after his deputy's death.
"But everybody that works in the courthouse has been on edge," Wood said.
The deaths may have an impact on prosecutors and attorneys elsewhere, attorney Pete Schulte told CNN affiliate WFAA.
Schulte said after someone shot through the windows of his Dallas offices in November, he began to carry a gun more often.
"It's going to have a chilling effect on people who do want to step into those roles and (have to think about whether to) start arming themselves," he said. "I mean, that's the risk that we're going to face now because of this happening."
A soldier, a psychologist and a DA
McLelland was an Army veteran who later earned a master's degree in psychology and became a psychologist for the Texas Department of Mental Health and Mental Retardation, the district attorney's website said.
He later earned his law degree and practiced as a defense attorney and mental health judge before becoming the county's district attorney in 2010.
McLelland and his wife leave behind two daughters and three sons. One son is a Dallas police officer.
The McLellands were killed almost exactly two months after Hasse was shot to death.
Hasse had feared for his life and carried a gun to work, said a Dallas attorney who described herself as his longtime friend.
Colleen Dunbar said she spoke with Hasse a week before he died. She said the prosecutor told her he had begun carrying a gun in and out of the county courthouse daily.
"He told me he would use a different exit every day because he was fearful for his life," Dunbar told CNN.
She said that Hasse gave no specifics on why he felt threatened -- only that he did.
A lingering promise
Before his own death, McLelland called Hasse "a stellar prosecutor" who knew that threats were part of the job.
He vowed after Hasse's slaying to put away the "scum" who killed his deputy.
"I hope that the people that did this are watching, because we're very confident that we're going to find you," McLelland told reporters.
"We're going to pull you out of whatever hole you're in, we're going to bring you back and let the people of Kaufman County prosecute you to the fullest extent of the law."
CNN's Ed Lavendera reported from Kaufman County; Holly Yan reported and wrote from Atlanta. CNN's AnneClaire Stapleton also contributed to this report.