By Pat Loeb

PHILADELPHIA (CBS) — Philadelphia mayor Michael Nutter has signed an executive order, mandating that the city’s prison system conform to federal standards in the prevention of what’s been called the “open secret” of incarceration: prison rape.

The mayor stresses Philadelphia already has a zero tolerance policy for inmate sexual abuse.

“When men and women, citizens of Philadelphia, are in our custody, it is our duty, responsibility and obligation to keep them safe and maintain their civil rights, even while they are in prison.”

He says the executive order assures it will continue since there is no other enforcement mechanism for local prisons.

He was joined by the director of his LGBT office, Nellie Fitzpatrick, because transgender inmates have the highest rate of victimization.

“I’m proud that Philadelphia has once again stepped forward to the front in recognizing and serving LGBT populations.”

Fitzpatrick says one new thing the executive order does is mandate training on LGBT issues for prison staff.