It happened on October 6 at the Mr. Cigarette Store located on the 400 block of West Cheltenham Avenue.
Authorities say 19-year-old Avery Armknecht walked into the store, produced a black-handled pocketknife and told the employee to open the register.
Exclusive video obtained by Action News captured the violent incident.
"He held the knife to her throat and a struggle ensued. Armknecht then stabbed the victim multiple times in the chest and fled the store," said police in a news release.
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Surveillance video captures Cheltenham Township robbery, stabbing
The 62-year-old victim was stabbed twice during the robbery and was taken by EMS to a local trauma center where she underwent emergency surgery. Police say she is expected to survive.
The victim is the store owner's mother, police said. The stabbing occurred in front of the clerk's 3-year-old granddaughter.
Armknecht fled the store after the stabbing but surrendered to Cheltenham Police on Monday.
He is facing charges of attempted criminal homicide, robbery, aggravated assault and other related offenses.