La policía encontró la pistola.

In Spanish, la policía is very often a singular collective noun meaning the police force or the police as an institution. Because it is grammatically singular, the verb is singular too: encontró.

Examples:

• La policía llegó rápido. = The police arrived quickly.
• La policía encontró la pistola. = The police found the gun.

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

• los policías = the male/mixed police officers
• las policías = the female police officers

Also, la policía can sometimes mean the female police officer, so context matters.

Encontró is the third-person singular preterite form of encontrar.

That means it can mean:

• he found
• she found
• it found
• the police found, if the subject is grammatically singular, as in la policía

The preterite is used for a completed action in the past.

Conjugation of encontrar in the preterite:

• yo encontré
• tú encontraste
• él / ella / usted encontró
• nosotros encontramos
• vosotros encontrasteis
• ellos / ellas / ustedes encontraron

The accent mark shows where the stress goes: en-con-TRÓ.

It is also part of the standard spelling of the third-person singular preterite ending -ó.

So:

• encontró = he/she/it found
• encontraron = they found

The accent is important because it helps identify the verb form clearly.

La is the definite article, meaning the.

So la pistola means the gun. It usually suggests a specific gun, one that is already known, mentioned before, or clear from context.

Compare:

• la pistola = the gun
• una pistola = a gun

Spanish uses articles very often, so having la here is completely normal.

Because la pistola refers to a specific gun, not just any gun.

Use:

• una pistola when introducing something for the first time or when it is not specific
• la pistola when the gun is identifiable or already understood from the situation

For example:

• La policía encontró una pistola en el coche. = The police found a gun in the car.
• La pistola estaba cargada. = The gun was loaded.

In your sentence, the speaker is treating it as the specific gun.

Because la pistola is a thing, not a person.

Spanish often uses the personal a before a specific human direct object:

• Veo a María. = I see María.
• La policía encontró a María. = The police found María.

But with things, you normally do not use the personal a:

• La policía encontró la pistola.

So this sentence has no a because la pistola is an object, not a person.

Yes, it could.

That is because policía can refer to:

• the police force: la policía
• a police officer, with gender shown by the article:
  • el policía = the male police officer
  • la policía = the female police officer

So La policía encontró la pistola could mean either:

• The police found the gun, or
• The female police officer found the gun

Usually, context tells you which meaning is intended.

Because pistola is a feminine noun in Spanish, so it takes la.

This is grammatical gender, not biological gender. Objects are assigned masculine or feminine gender in Spanish, and you have to learn the noun together with its article:

• la pistola
• el coche
• la mesa
• el libro

The feminine article here does not mean the gun is female. It only tells you the grammatical gender of the noun.

This is the normal, neutral word order:
subject + verb + direct object

• La policía = subject
• encontró = verb
• la pistola = direct object

Spanish word order is more flexible than English, but this version is the most straightforward and natural in many contexts.

For emphasis, Spanish can change the order, but that usually changes the focus:

• La pistola la encontró la policía. = It was the gun that the police found.
• Encontró la pistola la policía. = possible, but less neutral and more marked

So your sentence is the standard way to say it.

In standard peninsular Spanish, it would sound roughly like:

la po-li-THI-a en-kon-TRO la pis-TO-la

A few key points:

• ci in policía is usually pronounced like th in Spain
• encontró is stressed on the last syllable: -tró
• policía is stressed on -cí-
• Spanish vowels are usually short and clear:
  • a, e, i, o, u

So:

• policía → po-li-CÍ-a
• encontró → en-con-TRÓ
• pistola → pis-TO-la