On Monday, two assailants, a 17-year-old and an 18-year-old, attacked the Islamic Center of San Diego, the site of both a mosque and school, killing three adults. It was both a hate crime against a house of worship and a school shooting.In 1992, I stepped foot in the Islamic Center of San Diego for the first time. As an undergraduate student at UC San Diego, I was there to announce the creation of the Muslim Student Association, numbering only five students then. On April 24, I returned to the same center to give a lecture on modern Arab identity as...