The first interviews with Linda Heidt and Robin Heidt Cave will be aired as part of CBS’ “48 Hours Mystery” on Saturday night.

The episode, “Family Affair,” will look at the August 2008 murders of Philip Heidt and his son Carey Heidt. Another son, Craig Heidt, was convicted in December 2010 and sentenced to life in prison.

Linda Heidt, Philip’s widow and mother Carey, Craig and Chris, sat down with CBS correspondent Susan Spencer for her first and possibly only interview on what happened.

“I think that with a little passage of time, Linda just decided that she was willing to talk about it,” Spencer said. “What an awful thing to have gone through. We certainly would have respected her right to say ‘no.’ We really didn’t expect that she would agree. But she did, and more power to her.

“It confirmed the view of her in the community, that she is the decent, wonderful person to whom horrible things have happened,” Spencer said. “But she didn’t do it with an attitude of feeling sorry for herself.”

Spencer said Linda Heidt also unequivocally stated her belief that Craig did not shoot and kill her husband and son and also badly wound her with a shotgun.

“She wanted to say that she didn’t think that Craig had done this,” Spencer said. “She absolutely believes that he is innocent, and it was important for her to say that. She was very brave in describing what happened to her and what she did remember.”

In her interview with “48 Hours Mystery,” Linda Heidt said she saw a flash and it was completely dark in the room and that she could not identify the man who shot her.

“She’s certain it wasn’t Craig,” Spencer said.

Spencer said she asked Linda Heidt if she didn’t know who it was who shot her or if she knew for sure it was not Craig. Linda Heidt told Spencer she was sure it wasn’t Craig, “because I know my child,” Spencer related.

When asked if she had ever confronted Craig and asked him if he had killed his father and brother, Linda Heidt told Spencer she had done so and that Craig said he didn’t do it.

“She said she would not shield one son if he had killed the other and killed her husband,” Spencer said. “I was very impressed with her. She’s been through so much and was very composed.”

Spencer said she was surprised Robin Heidt Cave agreed to be interviewed and said Robin — Carey’s widow who was having an affair with Craig Heidt at the time of the murders — was hard on herself.

“She said the affair ‘was a mistake,’” Spencer said. “She said she was confused at the time and was infatuated with her husband’s brother. It was truly spinning out of control.”

Cave also believed Craig was innocent up until the approach of the trial, Spencer said.

“It wasn’t until close to the trial that little doubts began to plague her mind,” Spencer said.

The hour-long broadcast will air Saturday at 10 p.m. on WTOC. Squeezing the events of the murder and the trial into 60 minutes of air time was no small feat, according to Spencer.

“It’s always a challenge, particularly when things are this complicated,” she said. “But that’s the essence of television, being able to take something complicated and boil it down and make it make sense. This story is not without material.”

The show did try to get an interview with Craig Heidt but was unsuccessful in getting that arranged.