The Lincoln County Prosecuting Attorney and Lincoln County Sheriff's Office are cooperating with the U.S. Attorney in reviewing the Betsy Faria murder case, a press release from the Sheriff's Office said Wednesday.

According to the release, the collaboration has been ongoing for the last several months.

Betsy Faria was found murdered on Dec. 27, 2011, in the couple's Troy, Missouri, home. She had been stabbed 55 times.

Last year, Pamela Hupp was a key witness at the retrial of Russ Faria, even though she was never called to the stand.

Hupp was charged Wednesday with first-degree murder in the shooting death of 33-year-old Louis Gumpenberger of St. Charles.

A spokeswoman with the U.S. Attorney's Office said the office has been reviewing public record due to the nature of the case. She said the charges against Hupp did not change anything.