ALBANY, N.Y. — Gov. Kathy C. Hochul has chosen Brian A. Benjamin, a Democratic state senator from Harlem, to be her lieutenant governor, the second highest-ranking position in New York State, according to a person familiar with the decision.
Ms. Hochul, a Democrat from Western New York who was sworn in as the state’s first female governor on Tuesday, is expected to announce the appointment later this week.
The selection of Mr. Benjamin, who is Black, underscored Ms. Hochul’s attempt to diversify her ticket as she mounts her first campaign for governor next year, choosing a potential running mate who could help broaden her appeal in the voter-heavy New York City region.
Mr. Benjamin is the senior assistant majority leader in the State Senate, where he has been a vocal proponent of criminal justice reforms. He ran unsuccessfully for city comptroller earlier this year, placing fourth in a crowded Democratic primary.
Ms. Hochul’s office declined to comment. Mr. Benjamin, 44, who represents a large swath of Upper Manhattan, did not respond to a request for comment.
A lieutenant governor becomes governor when the governor dies, resigns or is impeached. He or she also serves as acting governor when the governor is absent or disabled.
But the position, which became vacant as a result of Ms. Hochul’s ascension after former Gov. Andrew M. Cuomo’s resignation, has traditionally served a mostly ceremonial role, entrusted with few statutory duties besides the formality of serving as president of the State Senate.
Over the past few weeks, Ms. Hochul had indicated that she intended to select someone from New York City. Ms. Hochul, who is white, approached a handful of city politicians who are people of color, including State Senator Jamaal Bailey, a rising star in Bronx politics; Assemblywoman Rodneyse Bichotte, the leader of Brooklyn’s Democratic Party; and Rubén Díaz Jr., the outgoing Bronx borough president.
A graduate of Brown University and Harvard University, Mr. Benjamin worked at Morgan Stanley and was a managing partner at Genesis Companies, a real estate firm with a focus on affordable housing, before entering politics.
In 2017, he ran for the State Senate seat vacated by Bill Perkins, who had won a seat in the City Council. He emerged as the Democratic Party’s pick for the seat after a convention vote in March and went on to easily defeat his Republican opponent in the overwhelmingly blue district, assuming office that June.
As a senator, Mr. Benjamin has backed efforts to close Rikers Island and supported legislation on a range of criminal justice issues, from ending cash bail and reforming discovery to ending solitary confinement and reforming parole laws.
He has also sponsored bills to get banks to divest from private for-profit prisons and create a so-called “rainy day fund” that New York City could tap into during fiscal emergencies. Mr. Benjamin said earlier this year that he supported the defund the police movement.
Michael Blake, a former assemblyman from the Bronx who endorsed Mr. Benjamin in the comptroller primary, stressed that he should be recognized for his skills and experience, not just how his race and standing among Black voters could aid Ms. Hochul politically.
“I think it’s important to realize that Brian is talented, and he is also Black,” Mr. Blake said.
“People are always paying attention to talent even when there is no success,” Mr. Blake added. “He ran for city comptroller — I think he was the most qualified — and lost, but at the end of the day, God had bigger plans for him.”
The competitive Democratic primary for comptroller included Corey Johnson, the speaker of the City Council, and Councilman Brad Lander, who emerged victorious as the standard-bearer of the party’s left flank. Mr. Benjamin finished behind Michelle Caruso-Cabrera, a former CNBC anchor who has never won elected office.
During the primary, Mr. Benjamin’s campaign relinquished nearly two dozen donations after The City raised questions about their authenticity.
Mr. Benjamin did not seem to gain significant traction in the race, perhaps raising questions about how many votes from New York City he could help Ms. Hochul attract as a running mate, especially if the governor faces a primary challenge from a person of color.
Jumaane Williams, the city’s public advocate, has said he is actively exploring a run for governor and Letitia James, the state attorney general, is considered a strong candidate, even though she has given no indication that she intends to run.
“Brian did not have a successful run citywide, but that doesn’t mean he won’t have a successful run statewide,” said Christina Greer, an associate professor of political science at Fordham University. “He has a financial background and could galvanize Black voters. He would translate well upstate.”
Mr. Benjamin is a close friend of Keith L.T. Wright, the chairman of the Democratic Party in Manhattan. On Wednesday, Mr. Wright praised Ms. Hochul’s choice.
“He’s bright, he’s intelligent and I think he’ll be a great pick,” Mr. Wright said. “I think he would be someone who would roll up his sleeves and get to work.”