Knoxville (WVLT) -- The attorney for the alleged killer in the Johnia Berry murder case is busy filing motions.

Late Friday afternoon as the clerk's office closed, Greg Isaacs filed a motion to suppress DNA evidence that was collected from Taylor Lee Olsen on July 27, arguing it violated his constitutional rights.

Earlier this week, Isaacs filed several other motions, including one asking for more information about another potential suspect, 24-year-old Noah Thomas Cox.

Cox has a lengthy criminal record including convictions for burglary and theft, but Olson is the only once charged.

Each man bears some resemblance to the composite picture that was circulated during the investigation.

Berry was stabbed more than 20 times during a robbery of her Knoxville apartment in December 2004.

Olson was taken into custody this September.

"I think the proper arrest was made,” said Joan Berry, Johnia’s mother. “If there are other people involved then absolutely, we want everyone involved, we want justice."

Isaacs says he can't comment.

The District Attorney General's office, though prosecutor John Gill would only say the following:

“I'm not sure why Mr. Isaacs filed this motion. He's aware that we are gathering evidence in this case which is subject to disclosure and as in any case, we will certainly disclose it as required by law."

We want to be very clear that Cox has not been charged with any crime in connection with Berry's murder and investigators won't comment on whether or not he is even a suspect.