Philadelphia- You would think that a woman who allegedly witnessed a co-worker plunge a knife into a porn actress the final few times after a photo shoot would run and tell police what happened.

Instead, Jennifer Mitkus allegedly stabbed Canadian actress Natel King twice after she was already dead, and then helped clean the crime scene, carry King’s wrapped and bound body downstairs and put it in the back of a sport utility vehicle, authorities say.

The Montgomery County district attorney’s office learned more of the Feb. 29, 2004, slaying of King, 23, after Anthony Frederick, 47, of Eagleville, admitted last week to being the killer. He is being held in Montgomery County Prison without bail.

During his confession, he told county detectives the role that his assistant, Mitkus, played. Mitkus, 30, was initially charged only with lying to police and hindering apprehension. She now faces nine additional charges, including abuse of a corpse.

Mitkus was told to surrender yesterday at 9 a.m. to the District Justice office but failed to appear. She turned herself in shortly after 3 p.m. and is being held in lieu of $75,000 bail.

“This was pretty vile conduct on her part,” said Montgomery County District Attorney Bruce L. Castor Jr. yesterday.

“You’d think she would have said, ‘I’m outta here,’ and go to police… She consciously chose to help the killer instead.”

She even did Internet research on Luminol, a chemical used by forensic investigators to identify crime scenes that have been cleaned and blood is no longer visible, Castor said.

Why Mitkus helped Frederick is unclear. “But right now she’s up to her eyeballs in it,” he said.

King, who starred in porn movies as Taylor Sumers, the Sexy Canadian, came to Pennsylvania for a photo shoot. She was last seen alive in Conshohocken on Feb. 29.

Her body was found March 23 in a rocky ravine in Whitemarsh Township. She was wrapped in large photography backdrops and blankets. She was naked except for a pair of white socks and had a red ball gag device strapped around her neck, according to the affidavit of probable cause.

She suffered multiple stab wounds to the chest and neck, and wounds to both hands, characterized as defense moves.

Frederick admitted to detectives that he killed King at the conclusion of the photo shoot in his studio on West 3rd Avenue in Conshohocken.

He said that as he stabbed her the last times, he noticed that Mitkus was standing near him at the base of the steps.

Frederick said he placed a gray blanket on the floor while Mitkus cleaned King’s blood off the floor.

He went upstairs to wash his hands and when he returned the knife he’d used to stab King had been moved. Mitkus, he said, later told him she stabbed King twice after she was dead.

They placed the bloodied cleaning supplies and towels into bags and discarded them, he told detectives.

Frederick said he threw dirt, sand and crumbling mortar over the basement floor.

He said he put King’s body on large backdrops from a suitcase. They searched for any evidence that could link them to the crime and wrapped them up with King’s body.

Together they carried her body outside and put it into the back of Frederick’s Honda Element, the affidavit said.

They decided Mitkus was going to drive King’s red Saturn away from Conshohocken while Frederick drove off with King’s body stashed in the back of his SUV.

He told police he pulled into the Wawa parking lot in West Conshohocken and took off his blood covered shirt and boots. He put them in a plastic bag, along with the Colt hunting knife he used to kill King.

He tossed the bag in a trash can. He then dumped her body over a guardrail on River Road in Whitemarsh Township.

He returned to Conshohocken to find Mitkus walking near King’s Saturn which was still parked near the crime scene.

She could not move the car because she could not drive a stick shift. She allegedly disposed of King’s cell phone that has never been found.

When investigators recovered a laptop computer from Mitkus’ Motel Six hotel room following her arrest, they found someone had accessed the Web site, “How Stuff Works,” and then searched for Luminol. The search was done at 2:12 a.m. March 23.

“We suspected all along she played a bigger role in this,” Castor said.