A construction worker prosecutors characterized as a leg-breaker for a rogue crew of Teamsters will remain jailed while U.S. District Court Magistrate Judge Judith G. Dein decides whether releasing him imperils the victims he’s accused of pummeling to a pulp and frightening out of pressing charges.

With his eight-months pregnant wife looking on at his 90-minute detention hearing yesterday, a fidgety Joseph “Jo Jo” Burhoe, 44, of Braintree also watched as Lt. Martin P. Conley, the state police gang unit investigator who busted him last week on extortion and racketeering charges, sifted through Boston police crime-scene photographs of another Teamster who accused Burhoe of smashing his face outside a South Boston watering hole in 2007 for not toeing the union line.

“You’d better shut your mouth about the Perrys,” Burhoe is accused of telling him during the beatdown.

Now-defunct Teamsters Local 82 of South Boston was run by co-defendant John Perry, 60, of Woburn, prosecutors say. Perry and Thomas Flaherty, 49, of Braintree, another former union member booted by the Teamsters last year, pleaded not guilty yesterday to racketeering and extortion charges.

Free on bond, they are accused of threatening and shaking down event organizers at hotels across the city, including a 2009 fundraiser for Gov. Deval Patrick, in order to drum up jobs for the union.

One alleged victim said Burhoe took him aside in 2009 and made “vague” comments “about deceased other members of the union. The victim took that to mean that maybe he’d be a victim,” Conley testified.

During the alleged 2007 tavern assault, Conley said Burhoe broke the man’s cheekbones, eye sockets and nose with a never-recovered blunt object, but the alleged victim refused to pursue criminal charges until two years later, when the feds took on his case.

“He said if he didn’t proceed (with charges) he’d be able to work,” Conley testified. “Then the harassment and intimidation began again in 2008.”

Burhoe’s public defender, Miriam Conrad, said he has a 1-year-old daughter and a stepchild with autism. “He is devoted to them,” Conrad said, “and he would do absolutely nothing to jeopardize their stability.”