The woman who drowned her four-year-old son in a bathtub on Tuesday night doesn't know why she did it, her lawyer said in court on Wednesday, as Israel grappled with a third murder of a child by its guardian, and the second drowning of a boy by his mother, within a week. Regina Kruchkov, 31, called emergency services at 10:20 p.m. on Tuesday, and whispered to the operator that she had killed her son before hanging up. The operator traced the call back to a south Tel Aviv address and dispatched paramedics and police to the home, where they discovered the body of four-year-old Michael lying on a bed. Kruchkov confessed to killing her son, police said, adding that no motive had been determined. Tel Aviv Magistrate Dan Moor on Sunday ordered Kruchkov sent to the Abarbanel Mental Health Center in Bat Yam for evaluation; she received the news with a blank expression. "When we discussed what she had done, she had no explanation," her lawyer, Avi Cohen, told the judge. "She began shaking throughout her whole body. Her head shook as well." He said Kruchkov should undergo testing by a district psychiatrist, and agreed to her remand being extended until September 11. She emigrated from the former Soviet Union, and she and Michael shared a small apartment near the Tel Aviv central bus station with her mother. Kruchkov's brother Vitali has an adjacent room with a separate entrance. "It's important to note, as unreal as it sounds, that on the day of the killing, Kruchkov had taken her son to kindergarten and brought him home," Cohen said. He described Kruchkov as a "very loving and dedicated" mother, and asked for the psychiatrist to help explain "the gap between the nature of the mother-child relationship and the incident." Moor scolded the police for arresting Regina's brother, an IDF combat soldier with no criminal record, and Michael's father, Yuri, for failing to protect the child. Moor agreed with the men's lawyers, who said police had no evidence connecting them to the mother's actions. Yuri and Vitali were released from custody. Although Yuri fathered Kruchkov's child, they never married. "What evidence do you have to link him [Vitali] beyond the fact that he lived there?" lawyer Neil Simon demanded of the police representative in court. Simon also blasted the police for not translating Vitali's written statement from Russian into Hebrew, and for failing to determine the time of Michael's death. "Our team has been working around the clock since last night. This is a complex investigation," the police representative said. He initiated an immediate appeal against Moor's decision to release the two men. "You can't be serious," Simon said in response to the appeal. "They were arrested by police to calm down the media and the public." The appeal was rejected. "The police do not have [even] a semblance of evidence to tie the two arrestees to the crime," Moor ruled. "They were not at home during the offense. There is no evidence of a criminal plot." After being released, Yuri attempted to identify his son at the L. Greenberg Institute for Forensic Medicine at Abu Kabir, but was sent away because he is not officially listed as the boy's biological father. Michael's grandmother, who is ill and bedridden, was at home during the killing, and would be questioned in the coming days, the police representative told the court. In the run-down neighborhood where Kruchkov lived, shell-shocked neighbors said they had no explanation for what happened, sounding eerily like the neighbors of Olga Borisov, the Rishon Lezion woman who drowned her four-year-old son off a Bat Yam beach on Friday night. "They were all good with one another," one neighbor said in Tel Aviv on Wednesday, standing on his third floor balcony. "I knew them for years; we spoke Russian to each other. Michael was always playing in the street. How could this happen?" Meanwhile, the Knesset's Internal Affairs and Environment Committee has scheduled a special session for next Wednesday to discuss the investigations of murders of children by their parents following the string of recent killings. The session will be attended by police, criminologists, welfare services officials, and National Council for the Child representatives. "The rapid succession of incidents in which helpless children are murdered by their relatives is creating a shocking picture where Israel is turning into a horror movie," Committee Chairman Ophir Paz-Pines said. "The committee will receive a report from the police on the progress of the investigations, and will demand answers to put a stop to this horrifying phenomenon."