By Todd Quinones

PHILADELPHIA (CBS) –Police are investigating two sexual assaults in Philadelphia’s Mayfair neighborhood.

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The surveillance video shows why police want this guy caught and get off the streets before he attacks another woman.

The video shows the suspect coming up from behind and suddenly grabbing and attacking a woman who was walking alone.

Just before the attack, the surveillance video shows him stalking her from behind. She has no idea what’s about to happen until it’s too late.

“I hear her scream ‘get your hand off my throat, don’t hurt me,’” said the Good Samaritan we are only identifying as Danielle.

Danielle stopped that attack.

It happened here in an alley near the 3200 block of Wellington Street in Mayfair just before one in the morning.

Danielle heard the 29-year-old victim screaming and ran out to help.

“He had her by her throat, her head against the wall and her pants coming down,” she said.

Danielle screamed at the man. He lunged at her.

He ran away and she chased him.

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“I was chasing after him screaming the whole time somebody call 911 he just tried to rape a girl. Call 911! That’s all I kept repeating,” Danielle said.

That attack on May 17th happened three weeks after another woman was sexually assaulted a few blocks away on the 3300 block of Disston Street.

“Both victims also describe some type of metal object that might have been placed against their necks,” Philadelphia Police Lt. Anthony McFadden said.

The first victim, a 23-year-old, was also walking alone late at night.

Danielle calls the surveillance video creepy. She says the second victim doesn’t feel safe.

“She’s doing better, she’s scared of course. We are all scared right now. This animal is on the loose,” Danielle said.

The suspect is being described as a white male or possibly a black male with a light complexion.

He’s about 20-years-old and stands about 6’ tall.

Anyone with information is asked to contact police at 215-686-TIPS (8477) or text a tip to PPD TIP or 773847.

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