After the Krim murders, mother Denise Albert told her 7-year-old son about the tragedy.
"Our older son reads the newspaper and is inquisitive," she said. "Our biggest fear was that he would hear from someone else. My kids have a babysitter. They need to know that they are OK. I needed to tell him to be very careful."
"We have built our company maintaining the very highest standards," said President Cliff Greenhouse, who is based New York City. "We are beyond strict. We won't see anyone without a complete accurate resume that does not have any gaps. The must display that they have long-term experience and stability – and are not here six months and there another six months."
The company prefers nannies who have worked for families for a minimum of two years and preferably five. And they recommend prospective families contact those who have worked with the nanny previously.
They do not require psychological testing, according to Greenhouse, but many families opt to do that on their own.
"We do not place people who have not gone through an in-depth interview with us," he said. "We look right in the eye and display that we care about them. And we do … Everyone here is passionate about helping families and finding caregivers that are the right match."
But ultimately, the employer makes the decision about who they will hire to work in their home with their children, according to Greenhouse. And most, like his company interviewers, "go by our instincts."
Greenhouse said he was personally affected by the Krim murders. "It hit close to home, not just as owner of an ad agency, but as parents – I've got three of my own. My wife and I were literally crying all night, it was so sad."
But Kelly Wickham, editor of the blog Mocha Momma, and an assistant principal at a middle school, said society is hard on working mothers who bear the brunt of the guilt when something does go terribly wrong.
The 41-year-old from Springfield, Ill., raised four children with the help of a nanny.
"She came into our lives with a certain amount of trust from a trusted friend, another mom," she said. "We had no problem and the children adored her."
But Wickham acknowledges that the family knew nothing of the nanny's past and put her under more scrutiny than a babysitter.
"What was she like with children?" they asked the prospective nanny. "Did she want children of her own? She was a single mom at the time. Whether her family was close and how would she interacted with our children. She must have a healthy sense of family and what belongs to her and what belongs to our family."
Still, she said people should not judge parents or nannies too harshly.
"And what happens when the kid is lost at the park -- it's no different from than me losing my own children at the park,' said Wickham. "I think that we need to be careful not to judge so quickly nannies and the people who use them. It's easy to jump on the bandwagon and beat up on moms."
And regulations won't solve the problem, according to Wickham.
"People trust in their family and friends for names more than an agency," she said. "It doesn't fix the issue. It could happen to my own children. You cannot control it when someone goes off the deep end. I feel bad for the mother and father. They probably didn't see the signs coming."
"At the time, you don't think – is this a psycho person?" said Wickham. "But it's a fear we all have. Are our children going to be safe and being cared for?"