A lot to unpack here. And maybe re-sorting. I've put this in chronological order. TL;DR: the abuse wasn't reported until recently, and he was deported twice between abuse instances and now.

Immigration Customs and Enforcement (ICE) confirmed that Lopez is an illegal immigrant who had been previously deported in 2015.
ICE said in a statement: "He was arrested by US Border Patrol (USBP) in near Lake Charles, Louisiana, on March 23, 2015, after having unlawfully entered the United States and was issued a Notice to Appear before a Department of Justice immigration judge. Alfaro Lopez was released on $7,500.00 bond on April 1, 2015, and ordered to report to the [Enforcement and Removal Operations] Baltimore field office."

[Doesn't sound like he was deported at that point, because...]

Police said the abuse occurred between 2016 and 2018 at the Elim Gaithersburg Church he had been teaching at in Maryland.
He allegedly admitted to his pastor that he had touched a girl inappropriately and that the issue had been "dealt with internally."

On Sept. 26, 2018, and immigration judge in Baltimore ordered Lopez to be deported from the US.
"ERO Baltimore arrested Alfaro Lopez on Jan. 23, 2019. The DOJ immigration judge granted Alfaro Lopez a voluntary departure from the US within 60 days of April 16, 2019," said ICE. "He left the US on April 30, 2019."
After being deported in 2019, Lopez illegally re-entered the US. He was apprehended again on March 9, 2020 in Rio Grande Valley, Texas. He was deported back to El Salvador on March 24, 2020.
ICE said it's unclear when he illegally returned to the US after the March 2020 deportation.

Now to recent events:

The first [abuse] victim came forward in May 2023, which resulted in three more victims informing police about the abuse between September 2023 and January 2024.
Ervin Jeovany Alfaro Lopez, 33, has been accused of sexually abusing at least three minors between the ages of 6 and 12 years old.
Lopez has been charged with sex abuse of a minor, second-degree sex offense, and third-degree sex offense, according to WUSA9.