By Tony Hanson

PHILADELPHIA (CBS) — Philadelphia police now have at least one piece of video, and they are searching for more, as they continue a relentless investigation into the murder of a young woman in front of her mother on Sunday evening in Northern Liberties.

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The chilling, sad video, which police were not yet prepared to release to the public, captures a cold-blooded, senseless murder.

Capt. James Clark says the two killers, both wearing hoodies, attacked the women as they passed them on the street.  He says one man takes Stephanie Long’s purse as the other grabs the purse of her 26-year-old daughter, Amber.

But Amber Long fights to keep her purse, Clark says, and in an instant the assailant fires a weapon.

Amber Long falls, dying at her mother’s feet (see previous story).

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“I have been in homicide almost six years,” Clarke said today.  “I will tell you this: after watching the video, this one of the saddest videos and situations that I have seen.  And we have all our guys up there working day and night to try to bring these killers in and have them arrested.”

It happened in the 900 block of North Front Street, near Poplar, at about 10:30pm.  Police believe the killers fled in a car, possibly a dark-colored Chevy, with a third person.

Clarke says police are virtually certain that someone saw something that will help, or knows who did this, and they are urged to call police.

There is a reward.

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