Stephen Nichols met Rhonda Casto in 2005, when Rhonda's mom, Julia Simmons, rented a spare room in Stephen's condo. Julia introduced Stephen to her daughter and he says his "jaw hit the floor" when he met Rhonda. They quickly became a couple.
And Baby Makes Three
Three years into their relationship, Stephen and Rhonda became parents. Rhonda adored her baby girl, and those close to Rhonda say she was an amazing mom.
An Aspiring Model
Rhonda was an aspiring model, and according to Nichols, she had gained some weight from her pregnancy. In order to get back in shape and keep modeling, he suggested they go on a hike for exercise.
A Troubled Relationship
Rhonda's best friend, Jessica Colburn, says the couple had been fighting leading up to the hike. According to Colburn, Rhonda told her that Nichols, "is either going to propose to me or kill me."
A Fateful Hike
In a new interview, Stephen Nichols walks "48 Hours" through that fateful hike that ended Rhonda's life, with new details he could not share before his trial. Nichols described the weather the morning of their hike as "perfect", and says the couple was in a great place in their relationship.
A Puzzling Question
Stephen Nichols says Rhonda asked him a puzzling question twice that day. According to Nichols, Rhonda asked, "if anything happens to me, would you promise to take care of our daughter?" Nichols says he thought the question was odd, but he said he would.
A Slick Trail
At some point during their hike, Stephen Nichols says it started to thunder and pour down rain making the steep trail slick. Nichols says Rhonda jokingly put a towel she was carrying over her shoulders and pretended to be Supergirl as she sprinted down the slippery path. Rhonda went off the trail and fell 150 feet to her death.
A New Story
When "48 Hours" first spoke to Stephen Nichols, he said Rhonda slipped and fell, and that her fall was a tragic accident. Now, he's telling a new story. Nichols says that Rhonda had long suffered from depression and that she may have chosen to go off the trail that day. He said there is one single footprint on the path where she went off; which could be evidence of a jump.
A New Story
There's more. Stephen Nichols says after Rhonda's fall, he hiked down to the bottom of the trail where she lay. He suggests that when he reached her body, she may have been still breathing. In a dangerous insinuation, Nichols then compares Rhonda to a wounded soldier who is put out of his misery because his injuries are too severe. Is Nichols admitting something serious to "48 Hours?"
What Really Happened?
Even though Rhonda Casto was on antidepressant and antianxiety medication, Rhonda's mother Julia Simmons says there is "no way she would have committed suicide." She says Nichols is lying and that he did push her off that trail.
Nichols Takes a Plea
Stephen Nichols pleaded guilty to criminally negligent homicide and coercion and was sentenced to time served. He is currently serving three years probation. He lives in Oregon and has not seen his daughter since the day he was arrested in 2015.