The police have arrested three key accused in last month's killing of gym trainer Asif Hussain Khan in Haryana's Nuh district which has sparked a major bout of religious unrest. It is also probing the veracity of a video of the Shri Rajput Karni Sena chief, Kunwar Suraj Pal Amu, making an alleged hate speech a few days ago in favour of those arrested in connection with the 27-year-old's death.