Natalie Grybauskas, a spokeswoman for Mayor de Blasio, said the city views transfers as the safest option for the inmates, but she conceded, “That doesn’t eliminate the possibility of any violence happening in any other jail.”

A spokesman for the Board of Correction, the city’s jail oversight panel, said it wants to see the practice minimized.

Albany is a two-and-a-half hour drive from New York City, and lawyers complain that inmates sent to the jail have missed court dates because they are transported late or not at all, prolonging their cases and pressuring them to accept plea deals.

The young men accused of assaulting Officer Souffrant were already facing serious charges like attempted murder, assault and gun possession. Correction officials believe they are gang members, an affiliation that leads to tougher bail conditions and sentences. Three of them had weapons when they arrived in Albany, a Bronx prosecutor recently said in court.

Last year, Mr. Cuomo, a Democrat, introduced regulations broadening oversight of solitary confinement in local jails, which the state commission is expected to adopt this summer. The regulations require jails to explain in writing any decision to place inmates in solitary for more than a month or to restrict or deny recreation and services.

In June, legislation that would have restricted the use of solitary in state prisons and local jails passed the Democrat-led Assembly, but stalled in the Republican-controlled Senate.

But even without these changes, advocates for inmates say the city’s practice of transferring young inmates appears to violate current law, which requires correction officials to send inmates to the closest suitable facilities and to take into consideration their lawyers’ and families’ ability to reach them.

Nancy Ginsburg, the director of The Legal Aid Society’s Adolescent Intervention and Diversion Project, which is challenging Mr. Francis’s transfer, said, “I think that nobody’s really paying attention to that.”