F.B.I. Seeks Victims of School Aide Accused of Sex Abuse Agents from the Federal Bureau of Investigation returned to a Brooklyn elementary school on Wednesday to continue an inquiry into a teacher's aide who was arrested this week after being accused of molesting children, possibly inside the school, and to search for more victims, law enforcement officials said. City education officials met on Wednesday with parents at the school, Public School 243 in Crown Heights, and sent home a letter alerting parents to the aide's arrest and providing a number they could call to reach F.B.I. investigators. The aide, Taleek Brooks, 40, who had worked at the school since 1995, had been out on bail after being arrested in January and charged with possession of child pornography. He was arrested again on Monday, and charged with producing child pornography, after federal agents discovered that videos on a computer taken from his home showed him engaging in sexual acts with students, law enforcement officials said. The videos appeared to have been made inside P.S. 243, the officials said. Mr. Brooks's lawyer and relatives have declined to comment. As a school system employee since 1991, Mr. Brooks had passed the city's fingerprinting and screening process, city officials said on Wednesday. He was suspended without pay by the city's Education Department after his arrest in mid-January. After an appearance in court on Tuesday, his bail was revoked and a judge ordered him detained. Parents at the school Wednesday morning were looking for answers. "What happened?" said Karisma Boynton, whose daughter attends kindergarten. It's crazy. It's shocking. I don't even know what to think anymore. Should I take her out? Should I leave her? The criminal complaint unsealed in court on Tuesday alleges two victims. The F.B.I. has established a hot line and is encouraging parents to come forward if they have more information. A memorandum sent to teachers on Wednesday by Karen Hambright-Glover, the school's principal, gave instructions for talking about the investigation with students, and announced that a crisis team from the teachers" union would visit. School officials held a morning meeting with parents in the auditorium, and sent a letter home in students" backpacks from the schools chancellor, Dennis M. Walcott. The F.B.I. "will not be interviewing any children without first reaching out to parents directly," the chancellor's letter said. The F.B.I. has also informed us that if they have reason to suspect one of your children may have been victimized by this individual, they will reach out to you directly. School officials had no comment on Wednesday. Outside the school were two Police Department vans marked "School Safety." Mayor Michael R. Bloomberg said on Wednesday that, given the size of the school system, it was inevitable that some school employees would behave criminally. "The school system's something like 125,000 people, and I don't think it's practical to think there isn't going to be somebody doing despicable things," the mayor said. There are some sick people in the world, and you just have to learn to deal with them. Parents at the school on Wednesday afternoon described Mr. Brooks as a familiar and friendly presence. "I know them by face," one parent, Alison Prescott, said of the teachers" aides. Mr. Brooks I know by name. Ms. Prescott, who has a daughter in the second grade and a son in kindergarten, said she frequently saw Mr. Brooks after school in the gym, playing basketball with students and teaching them how to dance. "I thought he was a gym teacher," she said. Vanessa Johnson, who has two daughters at the school, said she knew Mr. Brooks by sight. "It's a shock that this would be going on under your nose," she said. He was involved in everything, not just a teacher's aide. Ms. Johnson said school administrators had not told the parents enough about the situation. "I'm upset that I now am just hearing about this," she said. It was shocking to see news people and all of the police here. It's supposed to be a safe haven for them. You send your kids to school to be safe. It's sad. She said that she had asked her fourth-grade daughter whether she had had any inappropriate encounters with Mr. Brooks, and that her daughter had told her no. But Ms. Johnson said she still felt uneasy. "I think they should do more to know who's around our kids," she said. I don't think they do enough. Beth Kormanik, Kate Taylor and Brian Zumhagen contributed reporting.