Prisoner lost en route to Phila.

A prisoner en route from Florida to Philadelphia disappeared in the darkness, and authorities said yesterday that they were not sure where he escaped from the private transport van.

Sylvester Mitchell, 33, was wearing bright orange prison garb and shiny handcuffs and leg shackles when he slipped away early yesterday.

Mitchell, whose last known address in the city was in the 100 block of Nedro Avenue in Olney, is wanted here on charges of attempted murder and aggravated assault. He is known to frequent neighborhoods in West Philadelphia, North Philadelphia and Germantown.

"He's a dangerous felon," said Capt. Sharon Seaborough of Central Detectives. "If people know where he is, they need to contact us because they're putting themselves in danger."

It's unclear whether Mitchell fled from a van in Center City or in Annapolis, Md., where workers from a private transportation company last saw him.

Mitchell went on the lam in June after a shooting in the 5200 block of Wynnefield Avenue in Southwest Philadelphia. He allegedly shot two men he accused of robbing him.

He fled south, police said, adding that they were notified recently that Mitchell was in custody in Fort Lauderdale, Fla.

Prisoner Transportation Services of America L.L.C., based in Tennessee, was contracted to bring Mitchell and at least one other prisoner back to Philadelphia.

The van headed north, stopping for the break in Maryland. PTS workers told Philadelphia police they were sure Mitchell was still cuffed, shackled and in the van.

The van next stopped at the Ninth District in Center City about 3 a.m. yesterday to drop off the other Philadelphia prisoner. At that point, transportation officials said, they found out Mitchell, who was scheduled to be handed over to authorities in Southwest Philadelphia, had disappeared.

Ryan Whitten, PTS director of operations, said the company had no comment.

Mitchell is 5-feet-10, 185 pounds, with a dark complexion. He is clean-shaven, has short hair and speaks with a Jamaican accent. Anyone with information is asked to call Central Detectives at 215-686-3094 or Southwest Detectives at 215-686-3183.