A New York City storeowner has been convicted of beating a teenage boy in the head with a hammer, apparently ending his chances for an athletic career.

A surveillance video shows Salad Ahmed running from a side room of his Brooklyn grocery store and striking the 14-year-old with the heavy metal tool.

The district attorney's office says he was convicted Wednesday of first-degree assault and faces up to 25 years in prison.

Prosecutors say Ahmed beat the teen because he had been in a fight with his nephew, a cashier in the store. Ahmed claims the teen was shoplifting.

The teen has mostly recovered. He testified his speech is still slurred because of his injuries and he's no longer a star athlete.

Ahmed is being held without bail until his sentencing May 28.