Learn Farsi: پلیس فردا از مظنون بازجویی می‌کند. - The police will interrogate the suspect tomorrow.

In Farsi, it is very common to use the simple present tense for future actions, especially when a future time marker like فردا (tomorrow) is already in the sentence to make the timing clear. This sounds much more natural in everyday speech than the formal future tense (بازجویی خواهد کرد).

Why is the preposition از (from) used before مظنون (suspect)?

The compound verb بازجویی کردن (to interrogate) requires the preposition از to indicate who is being questioned. While English treats the suspect as a direct object ("interrogate the suspect"), Farsi literally phrases it as "doing an interrogation from the suspect."

Could I use the direct object marker را instead, like مظنون را بازجویی می‌کند?

No, you must use از. Because بازجویی کردن acts as an intransitive compound verb in Farsi, the person being questioned is the object of the preposition, not a direct object. Using را here would be grammatically incorrect and sound unnatural to a native speaker.

What kind of word is مظنون (suspect)?

مظنون (maznun) is an Arabic loanword that can act as both a noun (the suspect) and an adjective (suspected). It comes from a root word meaning suspicion or assumption, which you might also see in the related word ظن (zan), meaning suspicion.