Middlesex District Attorney Gerard T. Leone Jr. is giving “serious consideration” to running in the special US Senate race to fill John Kerry’s seat, he said Saturday.
Leone, 50, said he has received encouragement from friends and political allies to jump into the Democratic primary campaign — a race that already has two Massachusetts congressmen, Edward J. Markey and Stephen P. Lynch, battling for the party nomination. The primary will be held April 30.
“People I have a great deal of respect for have asked me to look at the race,” Leone said. “I will give it serious consideration, but my intention, as I announced last month, has always been to leave electoral politics.”
Leone, a former federal and state prosecutor who handled several high-profile cases prior to becoming district attorney, announced last month that he would not seek a third term as district attorney in the 2014 elections and had decided to leave public service.
“I am not running for another elective office,” Leone said at the time. “In fact, I intend to leave government service when I leave this office.”
Leone’s entry into what many thought would be a two-candidate race would spark a major shift in the campaign, crowding the Democratic field.
But Leone’s roots in Middlesex County could be a significant factor in his favor. The sprawling region stretches from the eastern Merrimack Valley and New Hampshire border towns to Cambridge and Somerville, and west to Newton and Framingham. Leone, who easily won election in 2006 and reelection in 2010, is well known in the county, which could help him win support.
About a third of those who are expected to vote in the Democratic primary live in Middlesex County.
In his career, the Hopkinton Democrat prosecuted some of the most memorable cases in state history, including those of attempted shoe bomber Richard Reid and British au pair Louise Woodward, who after her trial and appeal was found guilty of involuntary manslaughter in the death of a child in her care.
With Markey and Lynch’s campaign operations already established, Leone will face heavy pressure to make up his mind in the next few days. He must collect 10,000 certified voter signatures over the next four weeks to qualify for the primary ballot.
John Walsh, chairman of the state Democratic Party, said Saturday that he had not spoken to Leone about a potential run. “I have not talked to Gerry,” he said. “He’s obviously a very talented and respected person.”
Walsh and the party have not endorsed any Democrat, but the Democratic Senatorial Campaign Committee and senior party figures including Victoria Kennedy, the widow of Senator Edward M. Kennedy; former US Senator John F. Kerry; State Treasurer Steve Grossman; and Attorney General Martha Coakley have endorsed him.
Walsh said the party would welcome more candidates into the Democratic primary.
“I actually like competition, and I think the primaries are helpful for us,” Walsh said.
Conor Yunits, a Lynch spokesman, said his campaign would also embrace Leone as a primary candidate.
A Markey spokeswoman could not immediately be reached for comment Saturday.
Scott Brown’s decision on Friday not to run again left the Republican party scrambling for a potential replacement. Former state Senate minority leader Richard R. Tisei took his name out of contention Saturday when he announced that he does not plan on running.
“It’s not something I can see myself doing ... given the time constraints and the money you have to raise,” Tisei said.
Frank Phillips can be reached at firstname.lastname@example.org. Globe correspondent Zachary T. Sampson contributed to this