to take somebody hostage
vzít někoho jako rukojmí
It is up to you to decide if you are going to shoot him, take him hostage, or use him as a human shield. (Google)
Could one of those people present, suddenly get up with a gun and take him hostage? (Google)
If you kidnap somebody and take him hostage, you make him a hostage, that’s kidnapping and that’s against the law.(Google)