House Speaker Robert DeLeo meets with reporters.

HOUSE SPEAKER ROBERT DELEO’S campaign committee paid $100,000 in legal fees at the end of March to the same Boston law firm that represented him previously in his legal battles with US Attorney Carmen Ortiz’s office.

Campaign finance records indicate DeLeo paid $100,000 to Mintz Levin Cohn Ferris Glovsky and Popeo on March 30. The amount dwarfed all of his other campaign expenditures and represented about a third of his total outlays for the period ending Aug. 21. DeLeo raised $468,460 and spend $310,207 during the nearly eight-month period. His contribution total surpassed the $448,261 he raised in all of 2014, the last election year.

The payment to Mintz Levin is a bit of a mystery. DeLeo didn’t pay any legal fees last year out of his campaign account, suggesting his legal problems were behind him. Over several previous years, he had paid out close to $500,000 to Mintz Levin; in 2014, during the federal prosecution of top officials at the state Probation Department in connection with their hiring practices, the campaign paid $200,000 to Mintz Levin. During that trial, federal prosecutors labeled DeLeo an unindicted coconspirator but never charged with him with any crime.

A spokesman for DeLeo referred questions to Gemma Martin, the treasurer of the Speaker’s campaign committee. She said in an email that the expenditure in March “reflects monitoring the case over a long period of time,” an apparent reference to the Probation Department trial. The trial ended in July 2014, but the defendants are still appealing their convictions.

In October 2015, DeLeo asked Ralph Gants, the chief justice of the Supreme Judicial Court, to investigate who leaked to the Boston Globe a sealed deposition the Speaker gave in connection with an independent counsel’s probe of hiring at the Probation Department. After asking the US Attorney’s office, Attorney General Maura Healey, and the State Ethics Commission to look for the source of the leak, Gants responded to DeLeo on May 31, 2016, saying the SJC had failed to uncover how the deposition had made its way to the Globe. It was unclear whether Mintz Levin assisted DeLeo in appealing to the SJC.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...