Slideshow
Nessie, Marina, Leo and Lulu Krim in a photo on Marina Krim's online diary.
Live Journal
Nanny Yoselyn Ortega, her shirt bloody from an apparently self-inflicted throat wound, is wheeled away by medics at 57 W. 75th Street, after she allegedly stabbed to death 2-year-old Leo Krim and 6 year-old Lucia Krim, known as Lulu.
Warzer Jaff/Splash News
Marina and Kevin Krim, parents of Lulu and Leo Krim, who were allegedly killed by their nanny on West 75th Street on Oct. 25, 2012.
Patrick McMullan
The Krim children together in a photo on mother's Live Journal blog. Lulu, 6, (c) and her brother Leo, 2, (r) died on Oct. 25, 2012.
Live Journal
Leo, Nessie and Lulu Krim
Live Journal
Lulu and Nessie Krim.
LIve Journal
Marina and Leo Krim.
Live Journal
Lulu and Nessie Krim.
Live Journal
Lulu, Leo and Nessie Krim.
Live Journal
A blog posting shows Nessie Krim at a telephone booth in New York City.
Live Journal
Lulu, Nessie and Leo Krim in a photo from Facebook.
Facebook
Nessie Krim, in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption described her: "She is a wild child and is always making mischief. Nessie is her older sister Lulu's biggest admirer."
WeddingWindow.com
Lulu Krim in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption said, "Her three favorite cities are San Francisco, Manhattan Beach, and her current home New York City. Lulu loves art projects, ballet, and all things princess!"
WeddingWindow.com
Leo Krim in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption said, "Leo (1 year old) is Tera's nephew and is the first of the Krim's to be born in New York. He plans on learning how to walk in the next few months, just in time for the big day!"
WeddingWindow.com
Lulu Krim and her father, Kevin Krim, during a volunteer day in Central Park in November 2011.
DNAinfo/Sarah Tan
Ray Kelly told reporters at a press conference on Oct. 25, 2012 that the nanny who allegedly stabbed to death two children is 50-years-old.
DNAinfo/Victoria Bekiempis
Ray Kelly told reporters that the nanny alleged of stabbing to death a 1-year-old and 6-year-old was found on the bathroom floor with self-inflicted wounds.
DNAinfo/Victoria Bekiempis
Nessie, Marina, Leo and Lulu Krim in a photo on Marina Krim's online diary.
Photo Credit: Live Journal
UPPER WEST SIDE — Just days after a nanny allegedly stabbed to death two children in her care, parents across the city are still asking what they can do to make sure they can trust the caregivers they bring into their homes.
"Every time there's an incident like this, we get calls," said Corinne Keller, director of operations at the Parents League of New York, a nonprofit that provides information for parents across the city.
"'Did you hear about the incident?'" they ask, according to Keller. "'What can we do?'"
Marina Krim, wife of CNBC digital media senior vice president Kevin Krim, was returning home to her West 75th Street apartment Thursday night when she discovered her oldest daughter, Lucia, 6, and her 2-year-old son, Leo, lying in the bathtub with multiple stab wounds, police and neighbors said. As she ran screaming from the apartment, the building's superintendent rushed upstairs and discovered their nanny, Yoselyn Ortega, slicing her own neck with a knife, authorities said.
Lucia and Leo were pronounced dead at St. Luke's Hospital, NYPD spokesman Paul Browne said. Ortega was transported to New York Presbyterian-Weill Cornell Medical Center for self-inflicted wounds to her throat.
Charges against Ortega were still pending Monday morning.
"It brings to the surface the fears every parent has when leaving their children with anyone but family," an Upper West Side mother wrote on a blog Thursday.
"We can do all the background checks in the world, and we know that most caregivers are amazing and loving," she added. "But it's the random, horrific incidents like this that stay in our heads as we walk out the door and leave our children."
The heads of New York City nanny-placement agencies agreed.
"How? How? There is no explanation," said Chinthani Perera-Luneman, founder of Mom to Moms Advisor, which finds and matches nannies with families.
Still, she and others said there are steps parents can take to reduce risk when trying to settle on the right childcare worker.
Slideshow
Yoselyn Ortega, 50, in an online photo of her with two of the Krim children, including Lulu (R), who police say she killed with a knife in the family's home on October 25, 2012.
DNAinfo
Marina and Kevin Krim, parents of Lulu and Leo Krim, who were allegedly killed by their nanny on West 75th Street on Oct. 25, 2012.
Patrick McMullan
Lulu, Leo and Nessie Krim.
Live Journal
A blog posting shows Nessie Krim at a telephone booth in New York City.
Live Journal
Lulu, Nessie and Leo Krim in a photo from Facebook.
Facebook
Lulu Krim in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption said, "Her three favorite cities are San Francisco, Manhattan Beach, and her current home New York City. Lulu loves art projects, ballet, and all things princess!"
WeddingWindow.com
Marina Krim in a photo from a WeddingWindow.com page about her sister's wedding. The caption read: "[Marina] lives with her husband Kevin, their three adorable kids (Lulu, Nessie, and Leo), and very naughty greyhound (Babar) in New York City. Marina likes strolls in Central Park, doing art projects with the kids, and delicious food."
WeddingWindow.com
Nessie Krim, in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption described her: "She is a wild child and is always making mischief. Nessie is her older sister Lulu's biggest admirer."
WeddingWindow.com
The Krim children together in a photo on mother's Live Journal blog. Lulu, 6, (c) and her brother Leo, 2, (r) died on Oct. 25, 2012.
Live Journal
Leo, Nessie and Lulu Krim
Live Journal
Lulu and Nessie Krim.
Live Journal
Marina and Leo Krim.
Live Journal
Lulu and Nessie Krim.
LIve Journal
Leo Krim in a photo from a WeddingWindow.com page about Marina Krim's sister's wedding. The caption said, "Leo (1 year old) is Tera's nephew and is the first of the Krim's to be born in New York. He plans on learning how to walk in the next few months, just in time for the big day!"
WeddingWindow.com
Lulu Krim, 5, pushes a wheelbarrow as her dad, Kevin Krim, looks on. Both were participating in Family Day in Central Park near Mineral Springs Cafe.
DNAinfo/Sarah Tan
Lulu Krim, 5, pushes a wheelbarrow in Central Park near Mineral Springs Cafe during Family Day on Nov. 12, 2011.
DNAinfo/Sarah Tan
Nanny Yoselyn Ortega, her shirt bloody from an apparently self-inflicted throat wound, is wheeled away by medics at 57 W. 75th Street, after she allegedly stabbed to death 2-year-old Leo Krim and 6 year-old Lucia Krim, known as Lulu.
Warzer Jaff/Splash News
Yoselyn Ortega, 50, in an online photo of her with two of the Krim children, including Lulu (R), who police say she killed with a knife in the family's home on October 25, 2012.
Photo Credit: DNAinfo
Whether parents search for nannies on their own or hire an agency, one of the earliest parts of the hiring process is the interview: talking with applicants not only to learn their work history and references, but also to gauge their personalities, experts advised.
"Be thorough," instructed Ido Dotan, 30, who screens applicants and interviews families for Tami's Agency, which is based in Forest Hills. "There's no specific science or specific interview questions to be able to screen for certain things."
Instead, the goal should be to "find someone with a nice personality that you feel comfortable having around," he added.
After talking with applicants, parents should then conduct background checks, both through an online service and by taking applicants to be fingerprinted by the NYPD, experts said. The prints are checked against the department's records, but parents should also ask for a second set to send to the FBI as a way to safeguard against identity fraud, they advised.
"What I have found is that identification is available for sale — you can buy anything," Perera-Luneman said. "It's the only way of establishing identity in the United States."
If parents have hired an agency to find a nanny, they should ask explicitly whether the company performs background checks, experts added. Some, such as Tami's Agency, only conduct the checks on request and charge a $50 for the service.
Background checks, however, have their limits, experts warned.
"No background check is ever telling you whether you're dealing with the same person or not," Dotan said. "The background check, all it does is confirm the person's ID, whether you're a sex offender, whether you have a criminal record.
"It doesn't say what you would do in an emergency situation," Dotan added. "It confirms that you at least know who's in your house."
Instead, the decision whether to hire a certain nanny ultimately comes down to parents' instincts, experts said.
"Either you have that trust or you don't," Perera-Luneman said.