Learn French: Après s'être rendu, le suspect a vu le juge. - After surrendering, the suspect saw the judge.

The verb here is the reflexive verb se rendre (to surrender). Just like in the passé composé, reflexive verbs always use être as their helper verb in the past infinitive. So it becomes après s'être rendu instead of using avoir.

Why does the reflexive pronoun s' go before être?

In the past infinitive, object and reflexive pronouns are placed before the auxiliary verb (avoir or être), not before the past participle. Therefore, the s' goes right before être.

I know rendre means to return or give back. Does making it reflexive change the meaning to surrender?

Yes! While rendre means to give something back, the reflexive se rendre has two main meanings: to go to a place or, in police and military contexts like this one, to surrender or turn oneself in.

Would the spelling of rendu change if the suspect were a woman?

Yes, it would. Because the past infinitive here uses the helper verb être, the past participle rendu must agree with the subject it refers to. If it were a female suspect (la suspecte), it would be written as Après s'être rendue.