Das Opfer erkennt den Täter auf der Videoaufnahme.

Because Opfer is a neuter noun in German, so its singular article is das.

• das Opfer = the victim
• grammatical gender here is neuter
• this does not mean the victim is not a person; grammatical gender and real-life sex are separate things in German

So das Opfer can refer to a male victim, a female victim, or a person whose sex is not being specified.

Because den Täter is the direct object of the sentence, so it is in the accusative case.

• nominative: der Täter = the perpetrator
• accusative: den Täter = the perpetrator

Since the victim is doing the recognizing, das Opfer is the subject, and den Täter is the person being recognized.

German shows this mainly through case, not just word order.

In this sentence:

• das Opfer = subject, nominative
• den Täter = direct object, accusative

So the meaning is:

• The victim recognizes the perpetrator

not the other way around.

This is especially important because English relies more heavily on word order, while German often makes the roles clear through article endings.

No. The verb is simply erkennen.

• erkennen = to recognize / identify

The word auf does not belong to the verb here. It starts the prepositional phrase:

• auf der Videoaufnahme = on the video recording / in the video footage

So this is not like a separable verb such as aufstehen.

Not quite.

• kennen = to know, to be familiar with
• erkennen = to recognize, identify, realize

In this sentence, erkennt means that the victim can identify the perpetrator from the recording.

So:

• Ich kenne ihn. = I know him.
• Ich erkenne ihn. = I recognize him.

That is an important distinction.

Because auf is a preposition here, and it takes the dative when describing a location rather than movement.

Here the idea is roughly:

• the perpetrator is recognized on/in/from the video recording

There is no movement onto the recording, so German uses the dative:

• auf der Videoaufnahme

This is similar to:

• auf dem Foto = in/on the photo
• auf dem Bild = in/on the picture

German often uses auf with images, recordings, and screens where English might say in or on, depending on context.

Because Videoaufnahme is in the dative singular after auf.

The noun is:

• nominative: die Videoaufnahme

But after auf in a static-location meaning, it becomes:

• dative: der Videoaufnahme

Also, Videoaufnahme is feminine because the main part of the compound is Aufnahme, and Aufnahme is feminine.

Yes.

• das Opfer can refer to any victim, regardless of sex
• der Täter is grammatically masculine, but in traditional usage it can sometimes be used generically for a perpetrator

However, modern German may also use more explicitly gendered or inclusive forms depending on context, such as:

• die Täterin = female perpetrator
• der Täter / die Täterin
• inclusive forms in some contexts

In your sentence, Täter is just the standard dictionary form meaning perpetrator/offender.

Yes, as long as the finite verb stays in second position in a main clause.

For example, you could also say:

• Auf der Videoaufnahme erkennt das Opfer den Täter.

This puts more emphasis on the video recording.

What stays the same:

• the verb erkennt remains in second position
• the cases still show who is the subject and who is the object

So German word order is somewhat flexible, but the verb-second rule is very important.

Yes. German very often combines nouns into one compound word.

• Video
  • Aufnahme = Videoaufnahme

The last part usually determines the grammatical gender, so because Aufnahme is feminine, the whole compound is feminine:

• die Videoaufnahme

This is a very common feature of German vocabulary.