An inmate walked out of the maximum-security Maryland Penitentiary in Baltimore Sunday after signing out as a visitor. Police believe two visitors helped the prisoner escape.

Steven Lloyd Everett, 23, was still at large last night. The Baltimore man was serving a 50-year sentence for armed robbery. He also faces a life sentence in Sarasota, Fla., for assault with intent to murder and is wanted in Hopewell, Va., where he escaped from prison while awaiting trial on armed robbery charges.

Sgt. Michael Bass of the Baltimore Police Department said police also are looking for Edward Gray, 27, and Francis Robinson, 26, both of Baltimore, who police believe helped Everett escape.

Gray arrived at the penitentiary at 10:20 a.m. Sunday and asked to visit another inmate, Charles Hatfield, Bass said. Robinson arrived at the same time and asked to see Everett.

Everett was told he had a visitor, Bass said, but Robinson left before he came to the visiting room. Meanwhile, prison guards stamped Gray's hands with the word "Halt" in ink that can be seen only under ultraviolet light, a standard security precaution in the prison. Gray then went into the visiting area to see Hatfield.

Bass said Everett went to the same steps Gray had to use. Prison officials believe Gray rubbed one of Everett's hands so the ink, which was probably still wet, was transferred.

Everett then left the visiting area and signed out as Edward Gray. His hands were held under an ultraviolet light, and he was allowed to leave.

"Meanwhile, the real Edward Gray appeared," Bass said, "and either pretended that he had just signed the sheet, or pretended to sign it." When the officer on duty noticed the two signatures did not match, Bass said, Gray was detained briefly.

But when Gray produced identification, he said, guards allowed him to leave.