Complex sentence: At Palmer's trial, he claimed he had no idea Pickett was a trans woman until they began having sex; when he rejected Pickett, according to him, she attacked him and he was forced to defend himself.
Split into simpler sentences: At Palmer's trial, he claimed he had no idea Pickett was a trans woman until they began having sex. According to Palmer, when he rejected Pickett, she attacked him, and he was forced to defend himself.