Len, it is the personal a because the police are people too :-). Take a look at my serveral comments above. I still think that police is not an indirect object which would necesitate "le" before the verb as well as "a la policia". I think it is a direct object with no obligation for a preceding pronoun. Now watch the comments come rolling in.
I really struggled with this myself. It turns out the rules for the personal "a" contain some intricacies. It doesn't matter if the person is a stranger to you or not. Its true that the "a" is not used when saying something like "I need a plumber". That's because the "a" is not used for common names for people ("comunes de persona") that are preceded by an indefinite article (e.g. a plumber) and where such names are the direct objects of verbs that mean "búsqueda, preferencia o necesidad", e.g. "necesito un plomero".
However it is used "before collective names of people whose reference is determined or well-known", e.g. "la policía". You can view the whole list in the link below, link is entirely in Spanish language though: http://lema.rae.es/dpd/srv/search?id=ctMgM8Bp2D6ELPuNfg
I have read two explanations for why the "a" is there. One is that it is the personal "a" and that's it's required even if you're calling a building, such as a school or hospital, because you're not actually calling the building; instead, you're calling people in the building. When it comes to telephoning a building, I'm not sure that the "personal a" explanation is really correct.
That said, the "a" is still required (according to other people) because it clears up confusion. "Llamar" has several meanings. If you say simply "llamar el hospital," that would imply that you are calling it something, or giving it a name. If you are calling by phone, you'd say "llamar al hospital." So, in other words, when you are calling someone or someplace via telephone, you should use "llamar a" to clarify your meaning.
Whether it's the "personal a" or it's an "a" used to clarify the meaning of llamar, just remember that if you're calling someone or some place by telephone, use "llamar a." Hope this helps.
I do not believe the "a" here is a personal "a". Por ejemplo: You could say; "Ellos han llamado a un taxi or ...un taxi. It is also correct to say: Ellos han llamado a la ambulancia / a los bomberos. In all these cases there is no personal "a" but rather an urgency in the call.
Hola Lisagnipura, What about this? http://www.wordreference.com/es/en/translation.asp?spen=llamar I think llamar is transitive and calls for a direct object.
Hola Melita2: Thanks for the link. However, you will notice in the list of your reference, the fourth line down: the use of "llamar" as we are using it in this sentence:("telefonear"). It is is INtransitive and therefore takes no direct object.. Even the example shown is similar to our sentence: "Te llamo mañana" -- "te" is the indirect object. So.....to reiterate, in the sentence we are discussing, "le" can be used, but is not mandatory. Chau.
English is the only language I speak at all well and I was able to read and understand it, so I think it is in fact English.
I could see using something like that. You call to someone but they don't hear you. For instance, say the police were on the other side of a windy ravine from them. “They have called to the police, but the police did not hear them.” Seems like a reasonable usage. Maybe not a common phrase, but perhaps useful in noisy rescue situations, mountain sides, rapids, storms….
Hola Amiga Melita2: That always seems to be taught in beginning Spanish classes, but it is not always the case. (In any discussion of grammar, beware of the words "always" and "never"!!) Here are some links that explain: http://www.spanishdict.com/answers/190367/redundant-use-of-indirect-object-pronouns////spanish.about.com › ... › Parts of Speech › Pronouns////http://forums.tomisimo.org/showthread.php?t=12449//////////////Chau.