La víctima llamó a la policía.

Llamó is the preterite form of llamar, in the third person singular.

So it means:

• he called
• she called
• it called
• or you (formal) called

In this sentence, the subject is La víctima, so llamó means the victim called.

The preterite is used because this is seen as a completed action in the past: the victim made the call.

The accent mark shows where the stress goes: lla-MÓ.

It also helps distinguish it from llamo:

• llamo = I call / I am calling
• llamó = he/she called

So the accent is important both for pronunciation and meaning.

Because llamar normally takes a before the person or service being called.

So:

• llamar a la policía = to call the police
• llamar a María = to call María
• llamar al médico = to call the doctor

In English, we just say call the police, but in Spanish the a is required here.

Because in normal Spanish you usually use the article with this noun:

• la policía = the police

So llamó a la policía is the natural way to say called the police.

Without the article, llamó a policía, it sounds incomplete or unnatural in standard everyday Spanish.

In Spanish, la policía is often treated as a singular collective noun when it means the police force or institution.

So Spanish says:

• La policía llegó. = The police arrived.

Even though English uses a plural-looking idea, Spanish often uses singular grammar here.

If you want to talk about individual officers, you would say:

• los policías = the police officers

In this sentence, it most naturally means the police as a service or institution.

So:

• La víctima llamó a la policía. = The victim called the police.

Grammatically, la policía can also refer to a female police officer in some contexts, but that is not the most likely meaning here.

If you wanted to make an officer clearer, you might say:

• llamó a un policía = called a police officer
• llamó a una policía = called a female police officer

Víctima is a noun with feminine grammatical gender, so it takes la, even if the victim is male.

So both of these are possible:

• La víctima era una mujer.
• La víctima era un hombre.

This is about grammar, not necessarily biological sex.

So in your sentence, la víctima does not automatically mean the victim is female.

Yes. It is the same verb: llamar.

But the meaning changes depending on how it is used:

• llamar a alguien = to call someone
• llamarse = to be called / to be named

Examples:

• Llamó a la policía. = He/She called the police.
• Me llamo Ana. = My name is Ana.

So me llamo is a different construction, even though it comes from the same verb.

Because llamó presents the call as a finished event.

• llamó = called once, completed
• llamaba = was calling / used to call / called repeatedly, depending on context

So:

• La víctima llamó a la policía. = a single completed action
• La víctima llamaba a la policía. = the victim was calling the police / used to call the police

In a simple narrative sentence about one event, llamó is the natural choice.

Not in normal standard Spanish.

You normally need the articles here:

• la víctima
• la policía

So the natural sentence is:

• La víctima llamó a la policía.

Leaving out the articles would sound very unnatural in ordinary speech, though article omission can sometimes appear in very special styles like headlines or notes.