BOULDER — The last time Khadija Ahidid saw her son, he came to breakfast in 2021 looking “homeless” with big hair so she offered to give him $20 so he could go get a shave or a haircut that day. Hours later, he shot and killed 10 people at a King Soopers grocery store in the college town of Boulder. She saw Ahmad Alissa for the first time since then during his murder trial on Monday, saying repeatedly that her son, who was diagnosed after the shooting with schizophrenia, was sick.