(AP) — Joe Biden announced Thursday the four co-chairs of his vice presidential vetting team, starting the search for his running mate in earnest.

Former Connecticut Sen. Chris Dodd, Delaware Rep. Lisa Blunt Rochester, Los Angeles Mayor Eric Garcetti and Apple executive and longtime Biden aide Cynthia Hogan will serve as co-chairs on the committee.

They’ll work with vetting teams led by former White House counsel Bob Bauer, campaign general counsel Dana Remus and former homeland security adviser Lisa Monaco to evaluate Biden’s options and collect information on each candidate to help him make his decision.

“Selecting a vice presidential candidate is one of the most important decisions in a presidential campaign and no one knows this more than Joe Biden,” Biden campaign manager Jen O’Malley Dillon said in a statement. “These four co-chairs reflect the strength and diversity of our party, and will provide tremendous insight and expertise to what will be a rigorous selection and vetting process.”

Biden, a former vice president himself, has committed to picking a woman and has told donors his team is thinking about naming his running mate far in advance of the August Democratic convention.

Biden has offered some hints about his thinking. He frequently says he’s looking for someone who’s “simpatico with where I want to take the country.” He’s also said he can easily name 12 to 15 women who meet his criteria but would likely seriously consider from six to 11 candidates. Biden has given no indication of whether he’ll look to the Senate, where he spent six terms, to governors or elsewhere.

Those believed to be potential picks include some of Biden’s former primary opponents, such as Sens. Kamala Harris of California and Elizabeth Warren of Massachusetts, as well as some women outside Washington, including Michigan Gov. Gretchen Whitmer and former Georgia gubernatorial candidate Stacey Abrams.