(CBS News) In the battle against criminals, American prosecutors represent the people. So what is happening in Kaufman County, Texas, is striking the heart of our system of justice
For the second time, a prosecutor in the D.A.'s office there has been murdered, the killers unknown.
Employees showed up for work at the Kaufman County courthouse Monday escorted by armed officers after two assassinations in eight weeks.
Assistant District Attorney Mark Hasse was gunned down in broad daylight as he got out of his car just a block from the courthouse on January 31.
Saturday night, police found the bodies of District Attorney Mike McLelland and his wife Cynthia, both shot dead inside their home 12 miles from the courthouse in Forney, Texas.
"It would seem to me this is not just a random act. It would seem to me that there has to be some connection," said Judge Bruce Wood, the county's chief elected official. "This has to be more than a coincidence."
Police were back at the McLelland house today searching for clues. So far police are not commenting on whether there is any physical evidence linking the two cases.
Sources told CBS News the couple appeared to be getting ready for bed when someone used an assault rifle to shoot 65-year-old Cynthia McClelland in the head. Mike McClelland, 63, was hit several times in the torso.
It was Mike McLelland who issued a warning after Hasse was killed in January.
"We're going to pull you out of whatever hole you're in, we're gonna bring you back and let the people of Kaufman County prosecute you to the fullest extent of the law," he said at the press conference.
Later that same day, McLelland told CBS News he and Hasse had something in common.
"He did love getting bad guys," McClelland said on January 31. "It's something that we shared."
On Monday, Forney Mayor Darren Rizell urged residents to remain calm.
"We don't need to walk around in fear, need to calm down a little bit, pray for and support the McLelland families and support those that are handling the McLelland investigation," he said.
Later that afternoon, another officer was named temporary district attorney for the next three weeks. The governor will eventually appoint a replacement to complete the remainder of Mike McLelland's term, likely through January 2-15.
Police haven't revealed if they've found a connection between the two slayings, but sources tell CBS News correspondent John Miller - a veteran of the NYPD, LAPD and FBI - are looking into cases that McLelland and Hasse worked on together
One of the biggest cases involved the Aryan Brotherhood, a prison-based white supremacist gang.
"[Investigators] are looking at people who were involved with both prosecutors in trials and people who thought they were wrongly convicted - people who would have the mans, motive and opportunity, that motive being a grudge against the D.A.'s office," Miller said.