I just wanna throw my hat into the ring here.
First off, even though I have gone through several training courses in both offensive & defensive shooting techniques, to include several CQB courses, there is no way on gods green earth I would attempt a shot on a person holding a hostage, unless it was a contact shot-there is simply too many variables there, and I dont think I could honestly live with myself if I injured or killed an innocent person-particularly the child. I firearm used on the VEHICLE would be my option-it isnt jinking left or right, and is a rather large target. tires, radiator, and engine block. flat tires can be driven on, and if you hit the angle wrong, may not even puncture it. Or you can hit the rims (remember, at this point, your system likely dumped adrenaline, and your heart & breathing are accelerated). Better to shoot the front end-thats where all the vitals lie in the car. A cracked engine block will only go a short distance-same with a car with no coolant-once the engine is dead, thats it.
Now, put yourself in the abductors mind for a second, scary as it may be-he now KNOWS he has been identified (by you shooting at his car); what would YOU do? Ok, that may not be fair, but these people arent wired correctly. They likely will kill their captives, and possibly themselves, to avoid being caught. His WHOLE world just fell apart; this may not be the first abduction. This is a risk you take by actively engaging someone. Now, I am not saying DONT act, particularly if its your own child; I am just saying that, well, we arent superheroes-we let adrenaline take over, and the situation can potentially have a far worse ending.
Barring finding someone in my home, attempting to abduct my own kids, which is a whole different scenario, I would have to agree with Susan; Get as much info as possible-call 911 IMMEDITATELY....they record the call, and you can feed them the information. If needed, follow. If you were unnoticed, follow at a distance, feeding info. Let the police handle it-thats their job, not yours. If you arent familiar with the actors, yourself may be making a mistake-it could be, as someone stated, a parent picking up a child who is angry, and simply doesnt want to go home. again though, let the cops work that out.
I think that there are too many situations & variables to say with certainty what I would do. In my own home is a FAR different scenario than witnessing it on the street between strangers. In the first case, I would know that the situation isnt normal, and act appropriately. The second one, I would call 911, and follow, if possible-if not, I would feed them information actively as I am seeing it.
The human mind works in funny ways too...by recording what you are seeing, there isnt any guesswork. Most people wont remember the general details of the situation, simply because they are trying to focus on details. For instance, a "dark shirt" can be red, green, blue, black, grey. Thats kind of important if they pick him up immediately. Alone its nothing though. Which is why, IMHO, its best to call 911 IMMEDIATELY and report what youre seeing, before the person gets away. Cell phones are amazing technology; utilize it. There is no worrying about hitting someone else with stray rounds.

When I read this, the first thing I thought was... If my wife is present when you try to take her kids, first you are going to get shot, then she will probably get mad and do something worse.

Some women's self-defense tactics involve 1911s.

Greg

I think this is generally superb advice. But I'll throw out a few contrarian thoughts. First, I'd be very hesitant to shoot at any vehicle, especially one in motion. It's a very tough shot, perhaps less likely to disable the vehicle than you'd imagine, and it really raises the risk of bystanders getting hurt. Cars can do far more more damage than bullets, and streets and parking lots tend to be busy, chaotic places.

Second, I have what I call the "Mini-Mart Rule," which states "you might find me dead in a mini-mart, but you won't find me dead in the cooler of a mini-mart." In other words, I may or may not choose to resist or intervene in a holdup (probably not), but I will virtually always resist being moved or going to a second place at gunpoint.

Experience amply demonstrates that this is a potentially "game over" point of no return, one that dramatically increases the odds of getting killed. Likewise, very few children survive to return home from a kidnapping. Therefore, applying the rule, I would not allow a kidnapper to take a child away if I thought a)there was a reasonable chance to prevent it, AND b)I also thought that the cops were not likely to arrive very promptly.

Getaways can happen in seconds. Thereafter, the perp may get caught eventually, but the kid is likely gone. Some cops frustrated by these sorts of situations have bitterly remarked that their department's motto ought to be changed to "we arrive just after the nick of time" or "when seconds count, we arrive in minutes." I would not like my carefully noted description of the kidnapper to be used against him - at his murder trial.

Third, intervening by use of a firearm does not equate to discharging that firearm. In fact, the large majority of armed confrontations do not involve a discharged weapon, but only a presented one. Although you absolutely must be ready, willing and able to shoot if you present your firearm, you don't actually have to. Indeed, you often find, after drawing your weapon, that you can't shoot. This may be due to the lack of a reasonable shot, other persons in your line of fire, psychological factors, or other reasons.

Just my $0.02. But, overall, I'd say that the best advice remains what Old Solder wrote: "its best to call 911 IMMEDIATELY and report what you're seeing, before the person gets away. Cell phones are amazing technology; utilize it. There is no worrying about hitting someone else with stray rounds."

If I am _sure_ that a child is being kidnapped and I am _sure_ that I have a good shot, I don't care what the law says about the matter.

And I'm a lawyer.

The movie "Gone Baby Gone" makes this scenario much less black and white.

Very well said Jeff_M.

First, I want to say that my early comment about shooting at tyres was in the context of shooting at people; it was a step down in the violence, not a step up.

Second, even if you can't stop the vehicle, it can be useful to mark it so that anyone who sees it will notice its passing, and any police will likely investigate. It may also be noticed if taken to a garage for repairs. It can be better than nothing.

As I understand it, abducted children rarely survive the first 24 hours anyway. If the kidnapper does have to abandon the car in a hurry, they may not have time to kill the child. I appreciate your point about them not being rational, but it's still worth noting that there isn't much for them to gain by killing it. They've been seen by adults at the abduction, they probably used their own car and in any case will probably have left forensic evidence in it. Leave it alive will tend to distract anyone chasing them, and of course will look better in court.

Agreed; and I'm not saying DO act.