LEVITTOWN, Pa. (AP) — A pizza shop customer armed with a gun shot and killed one robber and injured another as they tried to hold up the Pennsylvania restaurant, according to police.

The shooting happened late Tuesday night at Porfirio's Pizza and Pasta, located in a shopping plaza in Levittown, about 25 miles northeast of Philadelphia.

The customer took out a gun and shot both men after they allegedly pistol-whipped him, Middletown Police Chief Joe Bartorilla told reporters.

One suspect was pronounced dead at the scene. The second suspect was taken to a hospital. His condition was not immediately available.

Bartorilla said the customer and two pizza shop employees were the only people in the restaurant when the two armed suspects walked in. The Bucks County Courier Times reported that the two employees were not hurt and the customer declined medical attention at the scene.

According to Bartorilla, the customer's gun was properly registered. Police were still trying to confirm whether the man had a concealed carry permit.

Police have not yet released the names of the customer or the two alleged robbers.

No other information was available early Wednesday morning. Police said the investigation was ongoing.

