The Oath

"I solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic..."

A lifetime ago, a young naval aviator took the Oath. Tom McGuire, now a San Francisco PD homicide inspector, hadn't thought about that Oath in years. That was all about to change.

A famous San Francisco newspaper columnist has been murdered. Some would say "executed". Shot through the head, her arms tried behind her, knotted together from shoulder to wrist.

McGui...