Dateline: Unforgettable Season 6, Episode 3 revisits the story of Heidi Firkus, who was shot to death at her residence on April 25, 2010. Firkus lived with her husband, Nick Firkus, in a neighborhood of Saint Paul, Minnesota.
Heidi Firkus was shot with a shotgun at the back of her, and died immediately on the scene. Moments before the murder, Heidi had made a frantic 911 call reporting an intruder trying to get inside the house. Heidi's husband Nick was rushed to the hospital with a bullet wound in his leg.
Initially, the case was considered to be a house burglary. But soon, authorities realised Nick had a troubled past, with financial difficulties. Dateline: Unforgettable Season 6, Episode 3 documents the complete story behind finding the murderer of Heidi Firkus. The episode, titled 65 Seconds, is set to air on June 19, 2025, at 8 p.m. EST on Oxygen.
What happened to the Dateline: Unforgettable subject, Heidi Firkus

As reported by CBS News, it was on the morning of April 25, 2010, when Heidi first made the 911 call reporting that someone was trying to break into their residence. Reportedly, the Dateline: Unforgettable subject, Heidi, was heard screaming after a loud noise.
Authorities believed that the loud sound came from a sound blast. 65 seconds after the call was hung up, Nick Firkus dialed again, reporting that he and his wife had been shot. As reported by CBS News, authorities found that the Dateline: Unforgettable subject, Heidi Firkus, was shot in the back of her head.
She was immediately declared dead on the scene, while Nick was taken to the hospital with a gunshot on his leg. As reported by CBS, when investigators inspected the crime scene and interrogated the neighbours, they reported seeing one man fleeing the Firkus residence.

Reportedly, one of the neighbours, named Brendan O' Connor, revealed that he listened to an argument coming from the Firkus residence, which was followed by a gunshot.
After receiving medical assistance, Nick Firkus made a recovery at the hospital. When he was interrogated, he revealed listening to someone trying to open the front door. Nick said that he grabbed a gun, made Heidi wake up, and then came downstairs to confront the intruder.
As per Nick's story, he had a struggle with the intruder. He said,
"So my finger slipped onto the trigger … she was running away, so I hit her in the back."
Nick reported that the intruder immediately fled away from the scene after they were shot.
Investigation on the murder of the Dateline: Unforgettable subject, Heidi Firkus

As reported by CBS News, when investigators investigated the history of the victims, they discovered that the victims were struggling financially. Reportedly, they were behind in paying the bills and had lost their house. On the day the Dateline: Unforgettable subject, Heidi, was killed, the couple was expected to vacate the house within 24 hours.
Nick Firkus, with the help of a sketch artist, provided the authorities with a drawing of the intruder. The picture was soon released to the public, but it garnered no concrete results. It was in 2012 when Nick Firkus again got married to a woman named Rachel Sanchez.

As reported by CBS, it was in 2015 when authorities received a major break in the case. A police tipster manages to find out the person whose face matched the description on the sketch. However, the man was soon excluded from the suspicion because he was already behind bars when the Dateline: Unforgettable subject, Heidi Firkus, was killed.
Authorities managed to find the true culprit behind the murder of Dateline: Unforgettable subject Heidi Firkus. As reported by CBS News, it was in 2019 when Sgt. Nichole Sipes received a major lead in the case. While going through the personal history of Heidi and Nick Firkus, the FBI found that the couple was struggling financially.
However, Sgt. Sipes concluded that the victim, Heidi Firkus, was unaware of it.
"There was no communication between the two of them to indicate that she had any idea of the depth of their financial issues."
It was predicted that Nick Firkus was hiding their financial breakdown from the Dateline: Unforgettable victim, Heidi Firkus. Sgt. Sipes said that Nick was concerned and ashamed about being responsible for the financial situation.

Authorities eventually found out that Nick Firkus had also divorced his second wife, Rachel Firkus. When Rachel was brought in for interrogation, she revealed that Nick had financial problems with her, similar to his first marriage.
As reported by CBS News, Rachel went on to provide audio evidence, which proved his lies. As reported by CBS News, it was on May 19, 2021, when the Dateline: Unforgettable culprit Nick Firkus was arrested and charged with second-degree murder.

The trial for Nick Firkus began in 2023, when prosecutors charged him with staging the crime scene after killing Heidi Firkus. The FBI used 3D models to recreate the murder scene, which proved that Nick's descriptions were fabricated. As reported by CBS News, authorities created an animation that showcased how the Dateline: Unforgettable subject, Heidi Firkus, was shot to death.
After a trial lasting for 11 days, it was on February 10, 2023, when Nick Firkus was found guilty. It was on April 13, 2023, when he was provided with a life sentence. However, Nick Firkus refused to plead guilty to the Heidi Firkus' murder. His trial is currently ongoing.
Check out our other articles to learn more about other cases on Dateline: Unforgettable.