Mark Hasse, chief felony prosecutor in the county, was gunned down January 31 outside the courthouse.

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Mark Hasse was gunned down as he walked across a parking lot to the courthouse.

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Eric Williams' wife, Kim, has implicated him in the deaths of Mike and Cynthia McLelland and Mark Hasse.

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The McClellands were killed about two months after one of McLelland's prosecutors, Mark Hasse, was slain outside the local courthouse.

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Mark Hasse, an assistant district attorney in Kaufman County, was shot to death while getting out of his car Thursday morning, sheriff's spokeswoman Pat Laney told CNN.

CNN: Prosecutor gunned down outside Texas courthouse

Burns said he and McLelland kept in touch "here and there" until January, when McLelland's assistant district attorney, Mark Hasse, was shot to death in a still-unsolved case.

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Nor are they sure whether the deaths are related to the killing of Kaufman County Assistant District Attorney Mark Hasse, who was killed on his way to work in January.

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Lewis said he couldn't discuss the investigation in further detail, including how the couple died and whether authorities believe their deaths are linked to the Jan. 31 fatal shooting of Mark Hasse, an assistant Kaufman County district attorney.

NPR: Texas District Attorney, Wife Found Dead At Home

The slayings came less than two weeks after Colorado's prison chief was shot to death at his front door, apparently by an ex-convict, and a couple of months after Kaufman County Assistant District Attorney Mark Hasse was killed in a parking lot a block from his courthouse office.

NPR: Texas DA Slain In His Home; Had Armed Himself