Dozens of people failed to report disturbing behavior by Nikolas Cruz before he committed the massacre at Marjory Stoneman Douglas High School in Parkland, Florida. The Sun Sentinel reports that more than 30 people knew about his troubling actions—such as killing animals or threatening to murder his mother—but only reported it after he killed 17 people on Valentine’s Day this year. “It’s very troubling behavior, and in many cases it probably should have caused them to report what they heard, saw or learned,” said Pinellas County Sheriff Bob Gualtieri, chairman of the Marjory Stoneman Douglas High School Public Safety Commission. “But for a variety of reasons they did not.” Before the massacre, Cruz reportedly killed a duck with a tire iron, shot squirrels, and decapitated a bird. However, two students who did report Cruz’s behavior say they were brushed off by the school’s administration and a tip to the FBI reportedly went unheeded. The parents of one Parkland student who was killed are suing the FBI for negligence, saying Cruz could have been stopped.