NY- In the end it was a simple smudged bloody fingerprint on a bedroom wall that convicted Catherine Woods’ killer yesterday.

Diligent NYPD officers found the incriminating mark as they searched the upper East Side apartment where the beautiful 21-year-old dancer had made her home until she was brutally slashed to death.

The print matched that of her jealous boyfriend, Paul Cortez, 26.

A Manhattan jury of four men and eight women took 11/2 days to convict the personal trainer and Boston University drama school graduate of murder yesterday.

Cortez, 26, of East Harlem, was stoic as the jury forewoman pronounced him guilty of nearly decapitating Woods in a rage.

“My daughter was a beautiful woman, inside and out,” Woods’ father, Jon, said outside her childhood home in Worthington, Ohio. “We’ll always remember her forever.”

Woods, a classically trained dancer, had followed her dream of Broadway stardom to New York after graduating from high school. But like so many before her, she soon found herself struggling – and turned to stripping to make ends meet.

Prosecutors said Cortez, a dreamy-eyed gym rat, left the bloody fingerprint on the wall of her apartment when he killed her – and that he had fantasized about murdering Woods in 24 notebooks filled with obsessive rantings.

He faces 25 years to life in prison when he is sentenced March 23.

“He had faith that the jury would do the right thing and set him free,” said Cortez’s lawyer Laura Miranda. “He’s in a state of shock.”

Another defense attorney, Dawn Florio, vowed to appeal, saying the judge’s decision to allow the jury to see Cortez’s writings – including lyrics to a song titled “Killin’ Machine” – doomed his case.

But Woods’ mom said the writings unmasked the real Cortez.

“The violence in them, the disdain for women. I was appalled,” Donna Woods said in Ohio. “It was hard to hear.”

From the beginning, Catherine Woods’ story read like the script from one of the Broadway shows in which she dreamed of starring.

The talented, dark-haired stunner moved to New York in hopes of working as a dancer or actress.

She dated Cortez, who grew up in the Bronx and attended private schools on scholarship, after meeting him at an Equinox gym near her E. 86th St. apartment.

She tried to dump him when he pushed her to quit stripping and demanded she stop seeing other men.

Prosecutors said Cortez waited outside her building until her male roommate left, then stabbed her repeatedly in the neck and left her to die Nov. 27, 2005.

The roommate, Woods’ ex-boyfriend David Haughn, returned, found the body and called the cops, who first focused on him as a potential suspect.

Suspicion quickly shifted to Cortez. He claimed he was at home at the time, but his cell phone records placed him right outside Woods’ apartment moments before the slaying.

Cortez also called Woods dozens of times in the hours before the murder, then abruptly stopped – a telltale sign he knew she was dead before the body was found, prosecutors said.

His lawyers tried to explain away the fingerprint as the result of a sexual encounter he had had with Woods when she was menstruating.

The killer’s mom wept openly in the courtroom when the verdict was read and defended him in a posting on his Web site later.

“My faith and love for my family are the only things that keep me going during this horrible ordeal,” Ivette Drake wrote on the gopaulcortez.com site.