We have no murders in our Los Angeles condominium building, but we do have mysteries.

Each case begins with something amiss. The security camera, unnoticed, witnessed the puzzling event. A board member, known here as The Great Rewinder, or GR, coaxes crucial information from the security camera, sole witness to the mystery.

Here are the stories. All are true.

The Heavy-Handed Houseguest

Our gym is nothing fancy, but it does have a complete set of weights. Some weight sets jump sizes in five-pound increments, but this one brackets the ten pounders with a pair of eights and twelves as well. Those sizes went missing.

I mentioned the absent weights to GR. He looked startled. He had a memory, of a car in the garage, with weights piled next to it. He knew the make and model of the car, and he knew who drove it: a houseguest of one of the owners.

The evidence was significant but still circumstantial. Rather than send a letter, I asked GR to chat with the owner.

He reported back. The owner said the houseguest was bad news. She didn’t know that the houseguest had taken the weights, but she wasn’t surprised. She had offered him a place to stay when he was down on his luck, and he had treated her badly. She looked upset. She offered to replace the weights. She mentioned to GR the date that he finally left.

Date in hand, GR examined the security footage. It was grainy but unmistakable: the houseguest, loading weights into the trunk of his car.

If there had been any doubt, there was none now.

Condo Security: The Mail Thief Who Wasn’t

A couple of years ago, after a rash of mail thefts, we did a security upgrade for our building. By studying footage, GR was able to determine how thieves were getting into the building. Among other things, we strengthened the front door and installed a new door entry system with a timer function, primarily so the postal delivery key—widely available on the street—was disabled at night.

Now, when we found an open package in the lobby, missing its contents, it brought back bad memories. Had mail thieves returned, despite our defenses?

Even before he began searching the video, GR had a hunch. The tenant of one of the unit owners was known to be thoughtless with his trash, to the annoyance of all.

The camera caught the culprit. That, plus his name was on the package. Conclusive evidence.

The board voted to impose a fine. Management notified the unit owner, who attended a hearing. He had already spoken with the tenant, who was contrite. The owner paid the fine, and the tenants have picked up their trash ever since.

The Dog That Peed

A simple puddle was the first clue to clandestine activity.

At 10:43 on a Monday morning, a board member spotted dog urine in the lobby.

In less than an hour, GR emailed security camera photos of a couple—the woman carrying a large pink tote bag—and a small dog.  GR knows everyone in the building, but he didn’t recognize them.

GR went back to the video footage, this time checking out the cameras on the lower level. The couple with the rude little dog appeared multiple times. They entered the building midmorning, went down to the basement level, showered in the pool area bathrooms and left a half hour later. 

How did they get in the front door? Video showed them punching in four-digits.

When we upgraded our entry system to keep out mail thieves, we programmed in a four-digit code for vendors that, like the postal key, worked only during the day. The code, we felt, was more convenient than giving our vendors a key to lose.

It worked well. Too well. Over time, a lot of owners, their guests, movers and various others used the code. Eventually the code got loose in the wild. Our system still barred entry at night but, we discovered, left us vulnerable during the day.

We hadn’t noticed the individuals who were regularly entering our building for a hot shower, although we should have paid better attention when our janitor complained about the atypical mess in the bathrooms.

Now that we knew about the intruders, we posted their photos—man, woman, little dog—on the front door and we changed the code. We give it to only a handful of trusted vendors and we update it often.

If their dog had been better behaved, or if they had cleaned up after her, they might have gotten away with it much longer. But the wet spot whet our interest.

For these three episodes, case closed.