THIS COULD be it - the big break that cops have needed in their monthlong hunt for the Kensington Strangler.

Investigators yesterday found video surveillance footage that offers a fairly clear look at the man they said beat and choked a 33-year-old woman in an alley on Sergeant Street near Kensington Avenue about 2 a.m. Monday.

"It's good stuff," said Capt. John Darby, of the police Special Victims Unit.

"Anyone who knows this male and looks at this video is going to be absolutely certain that this is the guy," Darby said. "We should be able to get someone to come forward and say that this is so-and-so."

Darby was quick to note that although investigators believe that the man shown in the video - a black male with a medium complexion, medium build and sideburns and carrying an iPod - is responsible for Monday's attack, it is too early to know if he was involved in the two homicides and two other assaults of women that have been linked to the Kensington Strangler.

"We're only talking about this particular case," he said, "but obviously he would be a person of interest in other assaults of women in that particular area."

Darby said the man seen in the video first approached the woman on Kensington Avenue near Huntingdon Street and introduced himself as "Anthony."

He asked if she wanted a date. The woman turned him down and told him her boyfriend was nearby, Darby said.

Darby said the surveillance footage, captured by a camera from a nearby business, shows the man casually strolling across Sergeant Street and then ducking into an alley, while the woman scans the area as if she's wondering where he got to.

The camera didn't capture the woman then walking by the alley, or the fiend ambushing her. He choked her, punched her in the face, struck her in the head with a rock and tried to stab her with scissors until she fought him off, Darby said.

Moments later, she is shown on tape staggering out of the alley and looking for help, he added.

That same dark, dingy alley was where a woman told police she was choked into unconsciousness on Oct. 31 and later came to and found that her pants had been pulled down.

She helped police develop a sketch of her attacker; that initial image appeared to come alive on the footage that was found yesterday.

Darby said the business owner whose camera filmed the assailant didn't realize he had part of the incident on tape.

Investigators discovered it when they returned to the area to "retrace their steps," he said.

He noted that investigators are still following up on the barrage of tips about the strangler that have been pouring into the SVU's office daily.

An employee at Community Legal Services, on Broad Street near Erie Avenue, claimed yesterday morning that a man who matched the description of the strangler entered the office and then fled when someone recognized him.

Darby said the man's physical description did not match the basic description of the attacker so they did not consider him a suspect.