St. Charles County, MO  (KTRS)  Evidence continues to mount in the murder case against Pam Hupp.

The “St. Louis Post Dispatch” reports that sources close to the case say Hupp purchased the knife she claimed Louis Gumpenberger used to kidnap her back in August. According to those sources, Hupp bought the knife just days earlier at a Dollar Tree store.

Hupp is charged with first-degree murder in the shooting death of the mentally disabled man. Investigators say Hupp killed Gumpenberger in an attempt to frame Russ Faria. Hupp was a key witness in Faria’s first murder trial in Lincoln County, which ended in a guilty verdict. Faria was later acquitted after he was granted a new trial.

This latest development comes after a report just days ago that a St. Charles County man came forward and claimed Hupp, posing as a “Dateline” producer, approached him to do a re-enactment for the TV show. This was allegedly the same method Hupp used to lure Gumpenberger to her O’Fallon home.

Hupp’s murder trial is set for May.