On the eve of trial, the defendant pleaded guilty to voluntary manslaughter in the May 2012 death of Louis Oliver and child abuse for choking two of his sons, hitting them with a belt and punching one of them in the stomach.
"This doesn't quite give us closure ... it's not enough time ... but it's a step," said the dead toddler's father, Michael Oliver.
"Somebody's taken responsibility, and that's what we wanted ... for somebody to be held accountable for the killing of our son," he said.
Once Nemeth is sentenced, Michael Oliver and his wife, Cristina, plan to begin work to bring changes to the childcare and daycare system so that allegations of abuse at such facilities will be fully investigated and made public.
"We were in shock that this day was coming, it's been a nightmare for us for the last four years," she said.
According to evidence presented at his preliminary hearing last year, Nemeth was alone with Louis for about an hour the afternoon of May 23, 2012.
A San Diego police detective testified that Nemeth said he woke the child up from a nap and found him to be a "little limp," putting him in a car seat while he tended to other children. Nemeth told investigators that when he turned his attention back to Louis, he found him unresponsive and not breathing.
Rooney said Nemeth lied about when he called 911, dialing the emergency number only after he talked on the phone with his mother for four minutes.
The toddler was pronounced dead the next morning. Doctors testified that he had severe retinal hemorrhages and suffered non-accidental trauma.
Rooney said the defendant shook Louis about eight days before fatally injuring him, but the child survived that shaking.
Another San Diego police detective testified that Nemeth's adult daughter told investigators that her father had a temper and yelled at children at his daycare facility, where she also worked. She told police that her father would become frustrated when babies cried, the detective said.
A former employee told authorities that she called Child Protective Services after seeing Nemeth push a boy down a hallway and press the boy's nose against a wall, a district attorney's investigator testified.
The Olivers said they continue to live with guilt, but they did what all parents should do when finding a potential daycare facility. They checked references and the state's child care licensing website -- a system they now see as flawed.
"It's very antiquated, for one; but two, it doesn't give a full picture of the facility, if there was a complaint or allegations of misconduct, they're not always listed in the file at the department of licensing," Michael Oliver said.
10News asked child psychologist Deborah Pontillo what to watch for if you're worried about what happens at your child's daycare facility. She said to look for a sudden change in your child's behavior and even drop in when you can.
"Sometimes if you can go in with the child and watch the child for a little bit, a half an hour, while they're in the daycare setting to see how comfortable they are with the providers, how they interact, whether they seem withdrawn or whether they seem withdrawn, engaged, whether they seem fearful," Pontillo said.
Do so periodically and if you have a child who can talk, it's OK to ask them about what goes one when you're not around, she added.
"You can leave it fairly open-ended so they can generate their own responses and just provide them a lot of feedback that it's OK to not like everything," Pontillo explained.