Like Ronald, Mollie was apparently murdered by an illegal immigrant. We don’t know all the details about Cristhian Bahena Rivera, Mollie’s alleged killer, but we know he was here because our government neglected its responsibility to keep him out.

Like my son’s murderer, there were probably numerous opportunities at which Rivera’s illegal presence could have been determined and acted upon. Instead of officials catching him using a false ID card and Social Security number, government at all levels apparently failed to see the obvious until it was too late for Mollie and her family.

The apologists for illegal immigrants will no doubt tell us that the vast majority of illegal immigrants are not violent criminals, and they are right. But that’s not the point. They are all violating laws that exist to protect the best interests of the American people, which is reason enough to enforce our immigration laws. The fact that my son, Mollie, Kate Steinle, Sarah Root and many more whose names never made the headlines are dead is all the more reason why our immigration laws must be enforced.