CALGARY -- Monday marks the four-year anniversary of one of Lethbridge’s most disturbing murder cases, the killing of 78-year old Irene Carter.

The grandmother was stabbed 16 times, pushed down the stairs and beaten to death by her daughter.

This week, the case is being featured on the CBC true crime series, The Detectives. The episode, titled Out of Lies, features a dramatic re-enactment of the case.

Sgt. Ryan Stef was a detective in the violent crimes unit at the time, and a lead investigator into the murder.

"The researchers at CBC liked the fact that it was a unique case, in that it involved a homicide where gambling was the main crux of the motive," he said.

The episode follows Stef as his team of investigators tries to uncover both the killer and the motive for Carter’s murder.

Carter was found dead in her home on Normandy Road in south Lethbridge in January 2016.

It Initially appeared the senior was the victim of a robbery gone wrong, but as the investigation progressed Stef and members of the violent crimes unit began to expose a web of lies that implicated a shocking suspect — the senior’s own daughter.

Lisa Freihaut was charged and ultimately pleaded guilty to second-degree murder in 2018. She is currently serving a life sentence and is not eligible for parole until 2029.

Lisa Freihaut - accused of murdering her mother

Lisa Freihau, pictured at an April 2016 news conference pleading the public for information about her mother's murder.(File)

Stef said the investigation was a long-term project that involved 90 police officers from Lethbridge, Calgary, Edmonton, Montana and Arizona. It also involved using a wire, and used stims — a tactic used to provide information to a suspect in hopes of getting a reaction from the person under investigation — to gather the evidence they needed to obtain a conviction.

One of the strategies involved organizing a news conference in April 2016 where Freihaut pleaded for information on her mother’s killing.

"That was a huge part of the investigation. At that time we knew that Lisa was a suspect." Stef said he wanted to gain Freihaut’s confidence, and keep her talking to police throughout the whole process.

The Detectives CBC still

A still from the CBC show The Detectives. Actor Sasha Roiz plays Sgt. Ryan Stef in the re-enactment. (CBC)

Stef, who is now a training officer with the Lethbridge Police Service, said he has presented the case and lessons from the investigation to fellow officers in Lethbridge, as well as at homicide conferences in Red Deer and Niagara Falls.

"It’s important not only to gather the conviction but also to prove the innocence of someone else who is a suspect."

Stef said the case also brings a focus on the power and strength of a gambling addiction "to the point where somebody is willing to commit murder, to get away with their addiction."

The Detectives combines a re-enactment of the crime and interviews with Stef to showcase the investigation and the creative techniques police used to uncover the truth. Actor Sasha Roiz plays Stef and Cat Lemieux portrays Freihaut.

Sgt. Ryan Stef

The real Sgt. Ryan Stef, pictured with his wife on the set in Montreal. (Submitted)

Actors also play two other members of the local investigative team, Sgt. Travis Evenson and crime analyst Melanie Legal.

Stef said Stg. Liam Breedon also worked with him “on every step of the file” but his contribution, along with the efforts of other officers, were rolled into the three characters featured in the episode.

"I really feel bad for that, but it was up to the producers on how to handle the casting and costing."

Stef has yet to see the full episode but has seen small scenes while he was in Montreal during the filming process. He said family and friends are planning a viewing party and he jokes other officers have given him the nickname "Hollywood".

The episode airs on CBC at 7:00 p.m. MST on Thursday.