The parents of a boy who is accused of killing four students at Oxford high school are missing and being searched for by law enforcement after the pair were also charged as part of the investigation into the mass shooting in Michigan. Jennifer and James Crumbley were charged with four counts of involuntary manslaughter. But in a shock twist, authorities then revealed that the whereabouts of the Crumbleys were not currently known, prompting law enforcement to effectively launch a manhunt for them with the Oakland county fugitive apprehension team. The Oakland county sheriff, Michael Bouchard, told CNN that a huge effort was being put into tracking the pair down. “Every available resource that’s there, it is happening. It is going on right now,” he said. Bouchard also said that he did not know if the Crumbleys were armed but cautioned members of the public not to approach them. “I would not encourage anybody to approach them. I think it would be unlikely [that they are armed], but we’re not going to take that chance. We’re going to go get them,” he said. But in a text message to the Associated Press, a lawyer for the Crumbleys said they had just left town for their own safety, but would return to face arraignment. Shannon Smith did not tell the news agency when they would appear in court. The parents were charged due to the issue of access to weapons. “The parents were the only individuals in the position to know the access to weapons,” the Oakland county prosecutor Karen McDonald said on Thursday. The gun “seems to have been just freely available to that individual”. Ethan Crumbley, 15, has been charged as an adult with two dozen crimes, including murder, attempted murder and terrorism, for the shooting on Tuesday at Oxford high school in Oakland county, roughly 30 miles north of Detroit. Four students were killed and seven more people were injured. Three were in hospitals in stable condition. The semi-automatic gun was purchased legally by Crumbley’s father last week, according to investigators. The parents were summoned to the school a few hours before the shooting occurred after a teacher found a drawing of a gun, a person bleeding and the words “help me” and “blood everywhere” and a laughing emoji, McDonald said at a press conference on Friday morning. Prosecutors have revealed more details of drawings and writings made by the gunman, suggesting the possibility that he was planning a shooting rampage. Authorities have previously said school officials met with him and his parents the morning of the attack to discuss concerns about his behavior. “Any individual who had the opportunity to stop this tragedy should have done so,” McDonald said. Parents in the US are rarely charged in school shootings involving their children, even though most minors get guns from a parent or relative’s house, according to experts. “Gun ownership is a right but with that right comes comes great responsibility,” McDonald said. There is no Michigan law that requires gun owners keep weapons locked away from children. McDonald, however, suggested there was more to build a case on. “All I can say at this point is those actions on mom and dad’s behalf go far beyond negligence,” she had told local station WJR-AM. “We obviously are prosecuting the shooter to the fullest extent … There are other individuals who should be held accountable.” McDonald said that Jennifer Crumbley had texted her son “You have to learn not to get caught” after a teacher saw him searching online for ammunition. She described the parents’ conduct as “unconscionable” and “criminal”. Sheriff Mike Bouchard disclosed on Wednesday that the parents met with school officials about their son’s classroom behavior, just a few hours before the shooting. McDonald said information about what had troubled the school “will most likely come to light soon”. Crumbley stayed in school on Tuesday and later emerged from a bathroom with a gun, firing at students in the hallway, police said. Tim Throne, leader of Oxford community schools, said the high school looks like a “war zone” and would not be ready for weeks. But he repeatedly credited students and staff for how they responded to the violence. Brady, the gun control campaign group, applauded the charges against the parents. Brady’s president, Kris Brown, said: “It is clear that these parents bear responsibility for creating conditions that allowed the tragic shooting at Oxford high school to occur. Safe storage saves lives and it fulfills an adult’s legal requirement to keep firearms out of the hands of minors. Doing less puts such adults in legal jeopardy, as we have seen here.”