Do car alarms really deter theft?
February 5, 2012 10:32 AM   Subscribe

Do car alarms really stop car thefts?

I realized last night when a car alarm was going off in our neighborhood that my reaction was more "Ugh, someone's car alarm is going off" and not at all "Hey, someone's car is getting stolen or tampered with!" In fact, never in my life have I ever made the connection between a car alarm and the assumption that the car is being stolen or tampered with.

I'm a Gen-X lifelong city dweller. My partner, raised suburban but city dweller for 15+ years, has the same reaction, or lack thereof. Car alarms are an annoyance and a thing you deal with when you live in the city, but they don't ever really denote the theft of a car. It's more like a temporary annoyance that elicits a shrug, not any concern for the car making the noise.

Anecdotally, I can imagine that if someone was going to steal a car and the alarm went off, it could potentially scare them off due to the noise. But never in my life have I ever seen anyone poke their head out a window or come running out of their house or building when the alarm goes off. It just goes off and eventually stops 10 or 20 minutes later. It's city white noise.

Have there ever been studies that show that car alarms stop car theft? Are there any interviews with car thieves that include discussion of car alarms and their value? Is there any non-anecdotal evidence anywhere that car alarms are anything other than just another noise?
posted by juniperesque to Travel & Transportation (13 answers total) 3 users marked this as a favorite
I have seen enough cars hauled off, alarms blaring, by towtrucks or flatbeds to wonder whether some of them were in fact being stolen.
posted by Ardiril at 10:43 AM on February 5, 2012 [1 favorite]

Best answer: According to AAA, they don't deter theft.

Wikipedia says the NYPD claims they make crime worse.
posted by vegartanipla at 10:43 AM on February 5, 2012

Best answer: And here's one of the reports linked to in the Wiki article about why the NYPD doesn't like them.

I don't know that an alarm going off after the breaking in has started is much of a deterrent, based on all these sources. But I do think that if you have a visible alarm light or such, it may have a slight deterrent effect and make the criminal more likely to pick the car next to yours without one.
posted by vegartanipla at 10:50 AM on February 5, 2012

I don't have a cite, but I believe a few states mandate that auto insurance rates are lowered with the presence of car alarms. Apply a little public choice theory and you can imagine where those regulations come from.
posted by benbenson at 10:55 AM on February 5, 2012

No. In my neighborhood, they serve as a skee-ball-style lights-and-sirens reward to squirrels that drop acorns on our cars.

(there's a story about squirrels, underemployment, a pneumatic potato gun, and a City of St. Louis Police detective that I could tell, but it doesn't serve to answer the question...)
posted by notsnot at 10:57 AM on February 5, 2012 [9 favorites]

Not sure about non-anecdotal evidence, but when I hear a car alarm going off in the wee hours of the night for more than 10 minutes, there's nothing more I'd like to do than hit the car with a baseball bat until the beast is dead. So in the sense of others having lesser restraint than my own person, I would suggest that car alarms may increase the likelihood of angry revenge hate tampering.
posted by oceanjesse at 11:33 AM on February 5, 2012 [1 favorite]

Car alarms work pretty great as proximity detectors: An alarm sounding may also mean some idiot has scratched/dented your parked car and is making off in a hurry.

I don't know that an alarm going off after the breaking in has started is much of a deterrent, based on all these sources.

The parking spaces at work (university campus) are somewhat remote, and traffic is pretty thin in the off hours. We get sporadic car break-ins and it looks like that the thieves will keep breaking into more cars as long as things keep quiet - an alarm may not save the car it is attached to, but it definitely helps the ones around it.
posted by Dr Dracator at 11:44 AM on February 5, 2012

My car alarm is extremely useful for finding my car in the parking lot.

However, there have been times with the alarm going off with me inside the car due to forgetting to turn it off and no one came running to stop me or even looked twice.
posted by Ghostride The Whip at 11:53 AM on February 5, 2012

A few years ago our car alarm went off. I opened the front door, didn't see anything suspicious, turned off the alarm, and went back to bed. The next morning I found evidence of somebody trying to jimmy the door, so I called the police. The police in turn lectured me about the stupidity of opening the door to investigate, as setting off the car alarm to get you to open the door would be an easy way to gain access to your house.

So in my case, yes, the car alarm averted a crime.
posted by COD at 11:55 AM on February 5, 2012 [2 favorites]

I imagine that if you heard your OWN car alarm going off, you would investigate, correct? But a stranger's car alarm is very annoying, indeed.
posted by two lights above the sea at 1:31 PM on February 5, 2012 [2 favorites]

I know a guy who broke into a car to turn the ceaseless alarm off at 3 in the morning. It had woken him up and he was pissed! No one else was around and no one stopped him.
posted by Obscure Reference at 1:48 PM on February 5, 2012 [2 favorites]

I hate, hate, hate them. But as just one anecdote, when we had a car that didn't have an alarm (2002ish Hyndai Accent) parked on our street, it was repeatedly broken into, and the level of damage done by would-be-thieves trying to start it seemed to indicate they'd had a long uninterrupted stretch of time with it. I've never had my alarmed car broken into on the street, and our neighbors don't talk about having their cars broken into much either.
posted by crabintheocean at 7:12 PM on February 5, 2012

NYC 20 or so years ago in the middle of the winter on a Saturday night...A car alarm started going off about 11 PM. It continued all night. All the windows closed and all, we were just blasted by this thing and we were on the 14th floor. Then at the first hint of dawn there was a lot of noise along with the blare of the car alarm. I looked out the window to see a guy in his skivvies and galoshes with a baseball bat beating the crap out of the car. First he got all the glass and plastic pulverized, then went to work on the roof. Finally, he worked over the front fenders and grill until he could open the hood. He ripped and tore everything he could out from the engine compartment, then used the baseball bat on all that remained. Eventually the alarm stopped. As if in a movie or something, seemingly hundreds of us opened our windows, leaned out of the apartments and cheered him lustily as he marched back to his building with the baseball bat raised in triumph over his head!
I don't think that car alarm was very helpful for anyone.
posted by txmon at 7:22 AM on February 6, 2012 [11 favorites]

« Older How can I make my report look professional?   |   How to network with higher ups while on the inside... Newer »
This thread is closed to new comments.