WASHINGTON (CBSNewYork/AP) — Dan Donovan, the Staten Island district attorney involved in the Eric Garner chokehold case, was sworn in Tuesday as the House’s newest member.

Donovan replaced Rep. Michael Grimm, who quit Congress after pleading guilty to tax fraud.

READ MORE: FBI Says Body Found In Grand Teton National Park Believed To Be Gabby Petito

Donovan easily won a special election last week to the vacant seat, which represents Staten Island and a small slice of Brooklyn. He is the only Republican from the five boroughs of New York City in Congress, representing a district that has many working-class white voters and is one of the city’s more conservative areas.

Donovan thanked family members and other supporters who watched from the visitors’ galleries as he took the oath of office, saying, “I promise to make all of them proud of my representation of them down here as a member of the greatest legislative body in the world.”

Donovan, 58, resigned Tuesday as Staten Island district attorney, a post he held for more than a decade.

He gained national attention when the grand jury he impaneled did not indict NYPD Officer Daniel Pantaleo in Garner’s death.

READ MORE: NYC Restaurant Owners Sound Off On Vaccine Mandate

That case was among several that have raised questions about police treatment of minorities in several cities.

Donovan took a House seat vacant since January, when Grimm resigned following his guilty plea. Grimm, who faces sentencing in June, had been re-elected to a third House term last November despite being under indictment.

The heavily Republican district re-elected Grimm even after his federal indictment in 2014 so political experts say Gentile faces long odds in the race.

By taking office, Donovan gives Republicans a 245-188 House majority. There are two vacancies in GOP-leaning seats.

Among those watching Donovan take his oath was former GOP Rep. Susan Molinari, who represented the district from 1990 to 1997 and is Google’s chief Washington lobbyist.

MORE NEWS: 2021 Primetime Emmy Awards: Complete List Of Winners And Nominees

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)