The police have the authority to arrest you if they have reasonable grounds to suspect you are involved in criminal activity. They must identify themselves as the police, inform you that you are being arrested, state the crime they believe you have committed, explain why your arrest is necessary, and inform you that you are not free to leave. If you are under 18, the police may only arrest you at school if it is unavoidable and they must inform your headteacher. After you have been arrested, the police must contact your parents, guardian or carer as soon as possible. The police can use reasonable force if you try to escape or become violent, such as holding you down or handcuffing you. Additionally, they also have the power to search you when you are arrested.