The phone books and Internet are full of private detective agencies touting services like surveillance, interrogation, covert operations, industrial espionage - and locating missing people. And most of them are run by security experts who earned their spurs in the police or one of the other security services. Sam Zonensein set up his own Tel Aviv-based agency after leaving the police, where he worked in a special undercover unit, in 1991. "It's a dream I've had since I was kid when I used to read Sherlock Holmes mysteries," says Zonensein, whose company generally concentrates on surveillance and security consultancy. However, he's had his fair share of missing persons. He says it's generally not too difficult to determine if a person is missing because they've disappeared or because something has happened to them. "It's easy to disappear intentionally for a short time, but not for long - maybe two or three weeks or a month. After that it gets difficult. These days, there's an electronic trail. If you use a credit card, go to your health fund or even the library, you can be found. It's the Big Brother effect," says Zonensein. If they can't be found through those means, then there's a good chance they've either had an accident or fallen victim to foul play. "There are different kinds of people who disappear intentionally. Someone with marriage problems, a cheating spouse or a husband who decides to run away instead of paying alimony. I get a lot of referrals to find a wife or husband, who is trying to put a lien on their assets. The other kind is someone who owes money to others and disappears to avoid paying or to save his life if it's being threatened," explains Zonensein. "There are cases in which people I've located can't believe I've found them. They've started a new life, maybe even have gotten married again, even though it makes them a bigamist. They're carrying on a double life, and when you find them it's a big shock." According to Eitan Newman, a detective for more than 20 years, first with an intelligence unit in the army and, since 1993, the head of Tel Aviv-based EMT Israel Investigations, there are a number of tried-and-true steps he takes to determine if a missing person has met with harm or is simply avoiding someone. "We have to discern if a person is missing because he simply wants to be alone or if he's hiding from something or someone - like a debt collector - and is actually a fugitive," he says. "We do a lot of field work. We start with the last place the missing person was seen. One time a Venezuelan journalist disappeared and his family contacted us. We started with his hotel, and at the same time we gathered information about his character from people who may have had encounters with him. Sometimes the family doesn't know the person as well as strangers do who meet him when he's away from home." Newman found the Venezuelan - he died of a drug overdose and was found with no ID or passport. The police sent him to the L. Greenberg Institute of Forensic Medicine at Abu Kabir, and then to a special cemetery near Beersheba for unidentified bodies. "We helped the police close this file by comparing the dental X-ray we got from the family with the sample they had from the body," he says. Both Zonensein and Newman say that taking on a case of a long-term missing person like Adi Yaakobi would be difficult. "The police have all the files, written interviews. Officially, they wouldn't usually cooperate with a private firm, but in a case like this, I think they might share their information. However, if the police think that maybe that someone might find something that shows they hadn't exhausted all possibilities, they might be reluctant to turn over information. They don't want to look bad," says Newman. Zonensein says he'd be realistic with the family before taking on the case and charging a hefty daily rate for his work. "I'd do an evaluation first and give them an estimate on the percentage of success. Ten years after a person disappears, he's not the same person anymore. Maybe Adi Yaakobi could be walking in the street and nobody would recognize her. There could be different hair, even a different face," he says. Despite the diminishing chances of their missing loved one ever resurfacing, Zonensein advises families not to give up. "A few months ago, I was working on a case of trying to locate a person. We found a body in the Jerusalem Hills that was in bad condition, and we couldn't tell if it was our client's missing person or another person," he says. "We worked with the police and Abu Kabir to take DNA and brought in the family for a test. Only then did we discover that it wasn't a match, and that the body didn't belong to their loved one. But imagine the tension and horror the family must have gone through when they did the test and waited to find out if it was their family member, and the mixed relief and sorrow when they found out it wasn't." And once in a while, the gumshoes even come across a happy ending. "There was a case where another tourist came here and he was bipolar," recalls Newman. "His family in Sweden hadn't been in contact with him for two or three months. We found him on the beach in Eilat living in a tent. We made contact with the family and got him hooked up with social services here. He was happy to be found. That was seven years ago, he's still here, and we're still in contact with him."