TROY, N.Y. -- One of the men convicted in the brutal beating of a Lansingburgh couple was supposed to be sentenced for murder Thursday. But an unexpected turn is threatening to change the entire case. 

This was not the sentencing hearing the Lockrow family was expecting. It seemed cut and dry -- Jacob Heimroth was convicted on two second-degree murder charges, but an entirely separate robbery case could change everything.

The family wife hoped for closure on Thursday, but instead they got confusion as they huddled around the Rensselaer County District Attorney, asking what happened.

"I'm not worried, I'm disgusted," said sister of Allen Lockrow walking away from the courtroom.

Disgusted that after a murder conviction in August, Jacob Heimroth wasn't sentenced as planned.

"Two brutal murders and they got to drag us through this. It's uncalled for," said Allen's older brother, Joseph Reilly. 

Heimroth's defense attorney, Joseph Ahearn, says his client's guilty verdict should be thrown out because the district attorney's office never told them a witness' son was being prosecuted by their office around the same time as the trial.

Justin Rist was arrested for robbing a gas station and threatening the cashier with a knife in September 2015. His case has nothing to do with the Lockrow murder, but his mother, Laurie Rist, is the neighbor who called 911 the night the couple was killed. 

"Based upon their suppression of that information from us, we were not able to cross-examine the witness on that, so that will be the basis of the motion," said Ahearn. 

"In good faith we had no idea that there was a relation between one person being prosecuted in our office and a witness in another case," said DA Joel Abelove.

Judge Andrew Ceresia will wait to decide on this motion until he gets it in writing next week. But he said to the DA's office, "Let this be a lesson."

"It is not a defense to say I didn't know about it," the judge continued.

He'll give the defense until Tuesday, October 11 to write a motion, and the prosecution has two days to respond. The defense is hoping for a re-trial.