The cops don't have a time machine and they don't give a shit about you getting mugged or your stuff getting stolen. If you work hard enough you might get a police report out of them for insurance purposes.

I don't have a good text source lying around but here's a law professor and a cop explaining the downside: https://www.youtube.com/watch?v=6wXkI4t7nuc

I've posted this before on HN, but will quickly cover it again; A few years ago, my wife was at school and (completely her own fault) left her purse in the class during lunch (this is a medical career school and the class had about 8 students). That night we received a call from Chase asking about a string of purchase attempts using one of her cards - which she then realized was missing. Based on the list of places the card was used, we went to the stores the following day explaining what happened. Once we had done the leg work, confirmed that they would have video surveillance during the time the card was used, we called the police. The officers that showed up went to great lengths to file the report, work with GameStop, Target and Stop&Shop security personnel to not only get us to identify the person, but get video evidence of the crimes at each location. In the end, the classmate who stole the card was prosecuted and served jail time in two separate counties as well as payment of damages (small, but still) for the attempted use of the card which got her nothing in the end. Coincidently, the detective on the case also saw that the girls mom had a warrant out for her arrest so they picked her up as well.

The experience was very positive from our side of things - and perhaps it's not the common experience people hear about, but these officers were very happy to help. As a side note, the county that these officers were in was not a small, nor "safe" county and it wasn't a matter of them not having anything else to do at the time.

All that being said, the original advice of not talking, and knowing your rights should definitely be adhered to if you are on the other side of things. The way everything was used to aide us, can also be used against you. Not all police will treat you the same.

There are some guidelines that I think can help. If you get stopped for a traffic stop and the cop says he wants to take a quick look through your car, you should (respectfully) decline. That can lead to nothing good for you. If you think you might be suspected of a crime (right or wrong), or you don't know why the police want to talk to you, do not go and meet with them. If you get arrested, get a lawyer and let him/her deal with talking to the police. You can talk to the judge if it comes to that.

If they explain that they are investigating a crime and you have some information or evidence they need, go ahead and help them if you are not a target.

Just remember, the police are not your friend. They do not care about your life. They will lie to you and manipulate you if it suits their purpose. However, they do in fact serve an important function, that you may need them someday. Use them for their intended purpose. The system is certainly imperfect, but does work much of the time. I believe the trend towards police wearing body cameras during every interaction can only lead to good things for everyone.

The only thing worse than cops is no cops.

Your experience is almost certainly the common experience for people in your socio-economic group. The common worst case being they do let it slide and you are just left with wasted effort on your part.

The problem is that you have no way of knowing ahead of time if you are going to get an outlier -- a cop who decides there is something hinky about you and focuses on that rather than whatever reason you solicited their help for. It is absolutely a rare event (somewhat less rare for other groups, but still rare). The problem is that the consequences of having one of those rare events happen to you can be life-ruining. It is a very real case of one bad apple spoiling the bunch.

In your example, you had nothing to gain from the culprit's arrest and prosecution. The chance of you ending up on the wrong side of the law was quite small, but not zero. Perhaps the purse was recovered and they found a joint in it - even if the drugs didn't belong to your wife, you risk becoming the target of an investigation.

Given that balance of low-chance, high-consequence risk with essentially zero upside it would make sense for most people in that situation to avoid it completely.

Their job is to get people in front of a judge, to make them pay fines, or to get them into prison. All things being equal, they'll be working with the closest target they can see and that's you if you solicit them. They basically behave like predators.

Where do you live? I want to make sure I never visit there.

At most, do the minimal reporting you have to so. The problem is, as a human you might innocently give the officer some cause to suspect you in some way, or in some way mitigate the crime against you. I know people who have felt more anger after the police turn up to do their thing than they did on discovering the crime.

I would only involve the police in something I felt was very serious, which had to be solved, and could not be solved any other reasonable way. My definition of something very serious? Don't know till it happens, and frankly I'm sure we all have our own ideas of limits.

Burglary wise, don't know about other countries, but here in the UK the only real reason to report a normal burglary is to get a crime number for the insurance company. Mugging is pretty much the same, assuming you have something stolen which is insured. And luckily that can be very minimal, Im think, cant be sure, you can report crime online and get an instant crime number for insurance purposes. I think it probably only worth it is people get physically hurt or something vital is stolen and can't be replaced. Even then...

I lived at the most populous neighbourhood in my city, and so I reported the theft to the police station, they made me enumerate my belongings and gave me some papers stating what I had lost.

A few weeks later, I called to inquire if some advance had been made, and the lady told me "no, we haven't recovered anything"... but I hadn't given her my case number ! So they hadn't recovered anything for anyone.. in a 100.000 people neighbourhood...

At least in my country, if there's no violence or some important reason to go after the criminal, police won't pursue. They don't care much about material losses (they do have a decent track record aprehending murderers and such).