Anything is possible when dealing with psychopaths, a police source said before embarking on yet another grim search of Tel Aviv's Yarkon River on Monday. A number of detectives from the police's central district had gathered near the Bavli bridge to scan the river's shores for a mysterious item, though they would not say what it was. Most of the journalists who had accompanied them already knew that Ronnie Ron had confessed to killing his four year old granddaughter and throwing a suitcase with her body into the river. Since then, police had scoured the river with underwater robots and scuba divers. Police thought they had found their target when a robot sent back images of what looked like a suitcase lying at the bottom of the river. But a subsequent visit to the river's bed by scuba divers found that the 'suitcase' was actually a large square rock, the police said. "We are here on another day of searching the area," a police commander told his detectives on Monday. "We will scan the riverbank from west to east. A girl of four and half, last seen wearing minimal clothing, is missing. Officers on horseback and search dogs will join the search," the commander said during the briefing. As the police presence on the Yarkon became ever more noticeable, detectives said information on what they were looking for had already gotten out to the local residents surrounding the river in north Tel Aviv, and accurately predicted that the media ban could not go on for much longer. It was lifted one day later. The police had to turn to a private company to obtain the underwater equipment, after a request for help from Navy was turned down. Since the watery search became publicized, police have dealt with a number of scathing criticisms, such as the claim that the company involved in the search did not have expertise in underwater technology. "We have paid thousands of shekels for very professional equipment - that criticism is wrong," a police spokesman said. On Tuesday, a sonar scanner attached to a boat was floated over the Yarkon. On Wednesday, a team of scuba divers with highly advanced equipment is expected to continue the search. Although police are basing their search on Ronnie's confession, detectives on the site stressed that there was no certainty yet over Rose's fate. "We just don't know for sure yet whether she is alive or dead," one officer said.