‘90s FAMILY : Who’s Minding the Sitter? : Is the baby-sitter a Nanny From Hell or a Mary Poppins? More parents are hiring detectives and screening agencies to find out.

The young parents knew something was amiss: Ever since they had hired a new baby-sitter two months earlier, their toddler had suffered recurring diaper rash and their telephone bills were unusually high.

With the help of a tiny camera concealed in a kitchen light, their suspicions were confirmed.

“The sitter was on the phone 95% of the day. She didn’t even take a break when feeding the little girl,” said New York private detective Joseph Cialone, who exposed the neglectful nanny on video.

Private investigator Nicholas Beltrante of Alexandria, Va., got the goods on another sitter before his clients had a chance to hire her. A background check revealed two out-of-state theft convictions, including a break-in at the home of a past employer.

While most child-care providers are trustworthy, with clean records, some conceal undesirable qualities or shadier pasts that make them unsuitable for many lines of work--most of all watching children. A growing number of nervous parents are hiring professional investigators like Cialone and Beltrante to weed out potential Nannies From Hell from the Mary Poppinses.

“It’s a building trend . . . (that) began about seven or eight years ago,” said Ralph Thomas, executive director of the National Assn. of Investigative Specialists in Austin, Tex. “All you have to do is sit down and read the newspaper and see the horror stories. It makes people think.”

A random sampling of private investigators shows more have been devoting part of their practices to investigating child-care providers in recent years. At the same time, businesses have cropped up to help working parents make the right baby-sitting choices or to keep tabs on sitters after they are hired.

Beltrante said he’s handling about 25% more child-care cases this year than last and expects even more next year. Many of his clients are working parents employed by the federal government.

Changing demographics are partly responsible for this growing business.

“Years ago, you were able to leave your children with your mother, or a sister or an aunt, but many people don’t have extended families they can count on. There are also more working mothers,” said Cialone, whose Flushing, N.Y., agency I on U Inc. gets several dozen child-care cases a year.

To be sure, 55% of women with children ages 6 and under are in the work force today, and most rely on outsiders to watch their kids. Only 20% use relatives, statistics show.

“There are more people looking for nannies than there are nannies available,” said Dana Friedman, co-president of the Families and Work Institute, a New York-based nonprofit research firm. “Most (nanny) agencies don’t do a good job screening . . . because most of them are just looking for warm bodies.”

Wendy Sachs, president of the International Nanny Assn. in Norfolk, Neb., and owner of the placement agency Philadelphia Nanny Network Inc., said the professional group has a list of recommended practices for nanny agencies to follow, but it has no policing authority. She admitted that some agencies do a better job of screening applicants than others.

She advised parents: “One factor you should consider is the (agency’s) fee. You have to realize you’re going to get what you pay for.

“It doesn’t mean the better agency is the higher-priced agency . . . but it is a factor to consider.”

Sachs said her nanny agency typically uncovers a criminal record in less than 1% of the applicants it screens and a bad driving record in about 2%.

What most independent investigative services promise is a thorough screening of job applicants within a week, including a verification of their identity and checks of their criminal background, driving record and credit report.

Such information doesn’t come cheap. Flat fees for most private investigators run between $250 and $500, Thomas said. Expect to pay more, usually between $50 and $65 per hour, if results must be expedited or if other information needs to be checked out, such as references or multi-state court records, he said.

Most require permission from the person being investigated, although some admit to having run checks without it.

The ChildCare Registry Inc., based in Danville, Calif., charges $140 for a pre-employment screening that uses a New Jersey private investigator to check a candidate’s criminal, civil and driving records, along with his or her educational background.

Many professional nannies also order checks of themselves and keep updated copies on file for future employment references, said Ellen Tauscher, a former Wall Street investment banker who founded ChildCare Registry two years ago. Tauscher said business is brisk, with an average 450 inquiries a month.

Detective Information Network in Annandale, Va., offers another service--a telephone hot line that tells callers where they can get the same information that private investigators get. The cost is $3.99 per minute, with each call averaging six minutes; DIN also can do the investigating for you for about $100.

“Most of this is public information anyway,” with the exception of credit reports, and even those can be accessed with an individual’s permission, said co-owner Frank Dillon, a former Air Force spy who started the company in January.

Dillon noted that half the states have centralized police data bases that can be publicly accessed, while all states maintain computerized records of motor vehicle violations. County courthouses will also keep records of criminal and civil cases.

The Florida Department of Law Enforcement, for example, can say if someone has been convicted of a crime in that state. The Illinois Department of Motor Vehicles keeps records of moving violations for four years, license suspensions for seven years and drunken-driving convictions indefinitely.

Because of privacy concerns, private citizens and most businesses don’t have legal access to the most comprehensive criminal records, compiled by the U.S. Department of Justice and maintained by the National Crime Information Center.

There are other limits. While job applicants may come up clean in one county or state, their records might be overlooked elsewhere if they failed to mention they had moved. That includes arrests during vacation.

Also, arrest records of their spouses or live-in companions wouldn’t be available.

“It’s a 50-state patchwork quilt and it’s a mess,” Tauscher said. “The sad thing is parents can’t do all this checking. Many are financially strapped as well as time-strapped.”