Khairullozhon Matanov is a 24-year-old former cab driver from Quincy, Massachusetts. The night of the Boston Marathon bombings, he ate dinner with Tamerlan and Dhzokhar Tsarnaev at a kebob restaurant in Somerville. Four days later Matanov saw photographs of his friends listed as suspects in the bombings on the CNN and FBI websites. Later that day he went to the …