Learn French: Nous n'avons interrogé personne. - We didn't interrogate anyone.

Usually in the passé composé, the second part of a negative pair (like pas or rien) goes between the helping verb (avons) and the past participle (interrogé). However, personne is a major exception! It always gets placed after the past participle.

Why isn't there a pas in this sentence?

ne ... personne acts as a complete negative package meaning "no one" or "not anyone". Whenever you use personne (or other specific negatives like rien or jamais), you must drop the pas.

Does personne mean "nobody" or "anyone"?

It translates to both, depending on how you phrase the English sentence! Nous n'avons interrogé personne can be translated as "We interrogated nobody" or "We didn't interrogate anyone." French uses the exact same structure for both ideas.

How does the n' affect the pronunciation of nous avons here?

Normally, in nous avons, you make a linking "z" sound (a liaison) between the "s" in nous and the "a" in avons. But here, the negative word ne (shortened to n') gets in the way. Because n' starts with a consonant sound, you drop that "z" sound completely.