PONTIAC, Mich. — Several months before the Oxford High School shooter searched for bullets online while at school and made violent writings on a worksheet, his mother sent messages to a family friend indicating she had concerns about her son’s mental health, court testimony in his mother’s trial revealed Friday. In April 2021, she texted the mother of her son’s lone friend that her son seemed “kind of depressed.” “I’m not sure if there’s something bothering at school. He really doesn’t feel good. I can’t get anything out of him,” Jennifer Crumbley wrote. “I’m not used to Ethan being moody. He’…