This week brought front-page news of a boundary-invasive, well-dressed couple at a White House dinner party; as well as a District of Columbia civil servant disappearing almost without a trace.[1] The stories have something in common.

We spend substantial time and money attempting to keep people and things out of places.[2] We also go to great effort to locate people and property when we want to know where they are.

All this activity has three basic forms: exclusion; the re-defining of relationships (e.g., Facebook®); and searching. Excluding and searching are more interesting categories from a technological standpoint, so I will provide examples in just those areas:

Excluding (or Securing)

Searching (and Locating)

Firewalls, jersey walls, regular walls, fences, TSA and DHS.

Lojack® for automobiles and laptops.

Encryption; biometric, holographic, caller ID and MAC address verification systems; password vaults; gated communities; security cameras; infrared and motion detectors; locks; safe rooms; and of course the traditional safe.

Toll road transponder tracing of putative adulterers; finding people by cell phone tower triangulation or the monitoring credit card utilization; and surreptitious vehicle tracking by G.P.S. recording device.[3]

Software against viruses, botnets, malware, spyware, trojans, and worms for PC’s; and vaccinations against H1N1 for humans.

Wireless shipment tags called “RFID”.

Life jacket and alpine climber rescue beacons.

Commercial aircraft flight data recorders.

Threats to security, property and privacy seem to be more prevalent than ever before; while our responses are increasingly costly, time consuming, and often times psychologically draining.

[1] Pam Butler (EPA employee, aged 47 and single) has been a missing person in Washington, D.C. for nine months. I believe she may have been killed by her ex-boyfriend, Jose Rodriguez-Cruz, for five reasons based entirely upon reporting I read in the Washington Post:

(1) The night that Butler and Rodriguez-Cruz broke up, according to his statements to police, he waited for her outside her single family home. If he did not have the key that evening, how did he happen to have it the next day, when he was an ex-lover and she was a missing person? Read on.

(2) Following the breakup, Butler was never seen again. Rodriguez-Cruz asserts this is coincidental, but I doubt it. According to the newspaper, he let himself back into Butler’s home not once, but on each of the following three days using a key. Butler was security-conscious. She probably would not have turned her alarm off for a former boyfriend or given him a key. If anything, she was more likely to keep the alarm on.

(3) If Butler gave a key to Rodriguez-Cruz, she also probably told him how to silence the alarm. Yet, our suspect claims he never received the alarm code. Having the key without the code and using the key to enter your former lover’s home for three days straight after a break-up is illogical. It is especially incredible for hours and hours of in-home presence while the homeowner is not around. Of course, if you are a killer doing cleanup then the alarm-free conduct makes perfect sense.

(4) Rodriguez-Cruz knew the alarm was off on the night of the breakup, if he was in the residence that evening. It is implausible he would foresee the lack of perimeter security thereafter unless he had something to do with Butler’s disappearance. How else would he expect access without an appointment? Even if a killer had come to the door after the breakup with Butler and the departure of Rodriguez-Cruz – but before Rodriguez-Cruz returned the next day, the odds are minuscule that some other rogue could pull it off. Look, no one else who knew Butler other than Rodriguez-Cruz, and no total stranger, would have possessed both the knowledge of that home’s security and the motive to remove her body in her bed sheets utilizing the window least observable by security cameras or neighbors. (Maybe Butler will be found stuffed in a wall, as was the fate of Yale University graduate student Annie Le. But I think Butler is more likely to have been carried out through her window.)

(5) Finally, Rodriguez-Cruz had to know Butler was vigilant about her own safety. Given that awareness on his part, why is it that during the three successive days following the romantic breakup — during which time Rodriguez-Cruz is reportedly visible on closed circuit video removing bags and bags through the front door – he did not call police? Did he fail to notice Butler was missing? Did he neglect to observe that the bed of his meticulous former girlfriend was stripped of sheets, that her alarm was continually off, that her real estate papers were not filed away, and that a dining room window blind was oddly positioned with the window unlocked?

In my opinion, the only thing between Rodriguez-Cruz and a homicide conviction may be Butler’s remains.

[2] The effort to keep foreign money and jihadist fighters out of Afghanistan is our most costly example.

[3] The legality of police hiding G.P.S. recording units under motor vehicles and retrieving them later without a warrant depends upon whether a particular state finds that a person’s itinerary on public roads carries a reasonable expectation of privacy. The U.S. Supreme Court will resolve differences of opinion about this, eventually.