Dallas --- While Dallas police haven't been able to catch a violent, knife-wielding robber, surveillance cameras caught his latest crime, a purse snatching outside an East Dallas gas station.

Surveillance video shows the suspect wrestle a woman to the ground as she was getting out of her car.

"He walks up to her and with no warning slams her to the ground," said Dallas Police Sr. Cpl. Janice Crowther. "As she tries to hold on to her purse, he is using that knife, trying his best to stab her ."

Sr. Cpl. Crowther said the purse may have saved the 28-year-old victim's life. "The knife went into the purse, instead of going into the lady," said Crowther.

The robber's getaway car was a 2008 black Dodge Avenger police believe he stole the day before in a carjacking at a car wash near downtown Dallas.