The mayor of Atlantic City has resigned, hours after pleading guilty to wire fraud charges.

“It is with a heavy heart that I tender my resignation as the Mayor of Atlantic City, effective immediately. I would like to apologize to the residents of the great City of Atlantic City,” Mayor Frank Gilliam Jr. wrote in a letter obtained by News 12 New Jersey.

Gilliam, a Democrat, admitted that he defrauded a basketball club out of $87,000.

The plea comes 10 months after the FBI raided Gilliam’s Atlantic City home. According to court papers, that FBI search found about $41,000 in cash – nearly half of the amount that he is said to have solicited under false pretenses.

Gilliam previously said in a statement that his actions are not connected to his conduct as mayor.

Several New Jersey leaders – including Gov. Phil Murphy – called for Gilliam’s resignation. Murphy called Gilliam’s actions “despicable.”

Gilliam could face 20 years in prison when he is sentenced. He also agreed to pay restitution.

Atlantic City Council President Marty Small will be sworn in as mayor Friday at 12 p.m.