Two Georgia-based soldiers have pleaded not guilty to premeditated murder in the case of the shooting death of a Fort Stewart noncommissioned officer who was gunned down outside his father’s home on New Year’s Eve.

A police officer in St. Joseph Township, Michigan, told a Berrien County judge on Wednesday that Spc. Kemia Hassel, 22, had spent months planning the murder of her husband, Sgt. Tyrone Hassel, 23, at the hands of her boyfriend, Spc. Jeremy Cuellar, 24, according to the Kalamazoo Gazette.

The two hashed out their plan over Snapchat, a social media platform that deletes picture and video messages as soon as they’ve been viewed, Mike Lanier told the court during the preliminary hearing. He testified that Spc. Hassel told police she planned her husband’s death, the Gazette reported.

The two were having an affair, country prosecutor Michael Sepic said in a January news release.

“The motive for the two to plot Sgt. Hassel’s death may have been to continue their relationship and reap the Army’s death benefit from his murder,” the release said.

Hassel faces one count of premeditated murder and one count of murder involving a family member and a gun. Cuellar is charged with one count of premeditated murder and one count of using a firearm to commit a felony.

They are both being held at the Berrien County jail, according to inmate records.

Investigators believe Spc. Hassel directed Cuellar to drive to Michigan in the days after Christmas, where the married couple were visiting Sgt. Hassel’s family.

Hassel was shot outside the home where the two were staying, as he returned from a New Year’s Eve gathering at his father’s house, the release said.

All three soldiers had been assigned to 1st Armored Brigade Combat Team, 3rd Infantry Division, Fort Stewart spokeswoman Dina McKain told Army Times in January. Sgt. Hassel had been stationed there since December.