I remember the first person I arrested for murder.  I had been out of the LAPD academy only a month or two, and my training officer and I were assigned a radio call known as a “welfare check.” These calls most often arise when someone is unable to contact an elderly relative or friend.  We went to the house in question, the home of an elderly widow, and found no evidence of a forced entry or any other outward sign of trouble.  But given the woman’s age and the accumulation of mail and newspapers at her front door, and as none of her neighbors had seen her in some time, my partner made the decision that we should break in.  We did so, expecting to find the woman dead of a heart attack, a stroke, or any of the other natural causes that claim people her age.

Yes, she was dead all right, but there was nothing natural about what had killed her.

When the homicide detectives arrived and assessed the scene, they told us it appeared that the woman had been raped and then stabbed to death with a kitchen knife.  The killer, having worked up an appetite, cooked and ate a meal as the woman lay dying in the next room.  To this day I am haunted by the thought of the terror she must have felt in those final moments of her life.  Who could have done such a thing, I wondered.

Later, with the detectives still sifting the crime scene for evidence, there was little for my partner and me to do but stand near the yellow crime-scene tape and keep the curious at bay.  A young man of about 20 approached and asked us what was going on, and in the most perfunctory of terms we told him that the woman in the house had died.  A detective in the house contacted us by radio and told us to step out of earshot from the man, and when we had done so the detective informed us we had been talking with the likely killer.

As an eager rookie, my inclination was to slap the handcuffs on him as quickly as I could.  My partner, with his greater experience and accompanying wisdom, played it differently.  He continued to engage the man in small talk, cleverly eliciting some admissions that would later prove valuable in the murder case against him.  We would come to learn that the woman had befriended the killer — a neighbor — some years before and often hired him to perform odd jobs around the house.  He had completed one such job before raping and killing her.

While the man struck me as a bit odd, to my then-untutored eye there was nothing in his demeanor that suggested he was capable of the horrible crime he had just committed.  In speaking with other neighbors later, I didn’t find one who wasn’t completely shocked by what the man had done.

Which brings us to the unfathomable, decade-long ordeal of Amanda Berry, Gina DeJesus, and Michelle Knight, the three women recently freed from their kidnapper in Cleveland.  How, we wonder, could one man kidnap and hold in captivity even one person for so long without being discovered?  How twisted must a man be to carry out such a crime not just once but three times?  And how can so twisted a person move among us without our detecting the depth of his malevolence?

We want to comfort ourselves with the delusion that we can spot the dangerous people in our midst.  We look at the man accused in the Cleveland case, Ariel Castro, and we tell ourselves we would have known something was amiss behind the walls of his ordinary looking clapboard home.  Never in my neighborhood, we say.

But the truth is that most of us haven’t a clue about what goes on inside our neighbors’ homes, even in those neighborhoods described, like Ariel Castro’s, as “tight-knit.”  As anyone who reads the papers knows, this term is most often a press euphemism for “poor” or “crime-plagued,” and indeed the Cleveland Police Department’s crime map reveals that officers in Castro’s neighborhood are kept busy.  Zoom in on the map to the area just south and west of the I-90/I-71 interchange, expand the date range from the last seven days to the last 30, 60 and 90, and watch the dots on the map multiply like so many poisonous spores in a Petri dish.