“Pedophile with 4 victims 10 counts,” Ms. Foxx said in the message. “Washed up celeb who lied to cops, 16. On a case eligible for deferred prosecution I think it’s indicative of something we should be looking at generally.”

She added: “Just because we can charge something doesn’t mean we should.”

Since January, the peculiar, roller coaster case involving Mr. Smollett has exposed an array of divisions and disagreements among Chicago’s leaders, and hundreds of text and email messages released this week from and to Ms. Foxx only underscored those tensions. The messages involving Ms. Foxx and her office also suggested that Ms. Foxx remained aware of developments in the case even as she publicly distanced herself from it.

The messages also paint a picture of a prosecutor’s office that failed at first to grasp the level of attention on the case, appearing overwhelmed by the criticism it faced when it abruptly announced in late March that it was dropping all of the criminal charges against Mr. Smollett.

Ms. Foxx, who was elected as Cook County’s state’s attorney three years ago amid criticism of her predecessor’s handling of a police shooting case, has faced her own firestorm over the Smollett case, and lingering questions about her role in it and about her office’s handling of it.

In February, Eddie Johnson, the Chicago police superintendent, held an impassioned news conference to accuse Mr. Smollett, who is black and gay, of staging an attack on himself on Jan. 29 to seek publicity. Mr. Smollett had told detectives that two men placed a rope around his neck, poured a chemical on him and used the phrase “MAGA country,” referencing President Trump’s campaign slogan. But Superintendent Johnson said the report was faked, flatly stating: “Mr. Smollett is the one who orchestrated this crime.” Mr. Smollett has maintained his innocence.