SHAH ALAM — The two defendants appeared in court with scarves wrapped around their heads, partially obscuring their faces. One of the young women spoke animatedly, hands awhirl as she bantered with her lawyers during a recess. Her relaxed demeanor belied the charges against them. Since Oct. 2, Siti Aisyah, a 26-year-old Indonesian, and Doan Thi Huong, a 29-year-old Vietnamese, have been on trial in a Malaysian courtroom for what prosecutors consider a brazen assassination. The court has seen the closed-circuit camera footage from Feb. 13 at the airport in Malaysia’s capital, Kuala Lumpur — aired on TV worldwide — that shows the two women sidling up to a portly, middle-aged man and appearing to rub their hands in his face. The man, who turned out to be 46-year-old Kim Jong Nam, the estranged half brother of North Korean leader Kim Jong Un, died shortly afterward from what an autopsy concluded was exposure to the lethal nerve agent VX.