Walsh aides want to delay extortion cases

Two top lieutenants of Mayor Martin J. Walsh are asking for a one-month delay in their extortion cases — a proposed reprieve that federal prosecutors are fighting.

The move comes just days after the U.S. District Attorney’s Office in Boston made a key change to the extortion and conspiracy charges it has brought against City Hall staffers Kenneth Brissette and Timothy Sullivan.

A second, superseding indictment filed Wednesday makes a highly technical but crucial change to the language accusing them of conspiring to extort Crash Line Productions, organizer of the Boston Calling music festival.

Under the 1946 Hobbs Act, which allows prosecution in commercial racketeering and extortion cases, public officials can be convicted if a jury finds they used “fear of economic harm” to obtain property — in this case, wages and benefits for union jobs that Crash Line told the city they didn’t need filled.

Brissette, the city’s director of tourism, sports and entertainment, and Sullivan, Walsh’s chief of staff for intergovernmental relations, are accused of telling Crash Line in 2014 that if it didn’t comply with their demands, the popular City Hall Plaza event would be picketed by union members, accompanied by a giant inflatable rat.

The trial is set for Jan. 8.