Kilmar Armando Abrego Garcia, the man who was erroneously deported to a prison in El Salvador earlier this year, was flown back to the United States on Friday to face charges related to transporting undocumented migrants.

For months, the Trump administration had resisted court orders instructing officials to bring back Mr. Abrego Garcia, who had been living in Maryland and had a special court order forbidding his deportation to El Salvador.

The fight thrust Mr. Abrego Garcia into the national spotlight, and he became the face of the political and legal turmoil surrounding President Trump’s crackdown on immigration.

Mr. Abrego Garcia appeared in federal court in Nashville on Friday evening. He was detained and is expected to return to court on June 13.

Here’s what we know.

What are the charges?

In court papers seeking his pretrial detention, prosecutors said Mr. Abrego Garcia had played “a significant role” in smuggling immigrants, including unaccompanied minors. A federal indictment unsealed on Friday also accused him of transporting firearms and narcotics purchased in Texas for resale in Maryland.

He appeared in Federal District Court in Nashville on Friday wearing a short-sleeved, white, button-down shirt, The Associated Press reported. Through an interpreter, he said he understood the charges.