By Adrienne Moore

SACRAMENTO (CBS13) — A final step toward closure was delayed Monday in the murder case of Grant High School football player JJ Clavo.

The District Attorney’s office said a woman has come forward claiming her boyfriend told her multiple times that he killed JJ Clavo. Now, both the DA’s office and the defense attorney are investigating this claim, making for a day Clavo’s mother says she never saw coming.

The woman apparently told investigators about this alleged confession last December, but that information just recently trickled down to people in the DA’s office.

READ: JJ Clavo’s Mother Speaks Out After Her Son’s Murderer Was Found Guilty

“I don’t believe there is any credibility to the statement,” Nicole Clavo said. “None of the victims, nor witnesses who have testified in this case, ever said anybody was over the age of 40 plus, so it’s surprising to us all.”

Nineteen-year-old Keymontae Lindsey was recently convicted of killing JJ Clavo back in November of 2015. The 17-year-old was shot inside his car while getting food before a playoff football game with a friend.

On Monday, when Lindsey learned his sentencing was being pushed back, he was heard turning to his attorney saying, “Man, this is a joke.”

ALSO: Teen Found Guilty In 2015 Murder Of Grant High Football Player JJ Clavo

Lindsey’s mother spoke to CBS13 after the hearing.

“This will be appealed. I don not agree or respect the judge’s decision. There was not enough evidence for him to find my son guilty So today wouldn’t have been a final day regardless,” Ranika Moore said.

Lindsey’s sentencing date has been set for October 4th.

Adrienne Moore