Antonio Lehmann, the owner of book retailer Librería Lehmann S.A., was murdered in Verbana Café and Restaurant in Tres Ríos, just east of San José, on Sunday night at 7:30 p.m.

According to eyewitness accounts, three men stormed into the restaurant wearing handkerchiefs over their mouths, dark sunglasses and hats. One was armed with a gun and another with a knife.

The suspects entered to rob the business, according to National Police reports. Lehmann, who was eating dinner with a friend, confronted one of the men and was shot once in the chest. He was 75 years old.

A total of three tables were occupied in the restaurant on Sunday night. One of the suspects robbed a wallet containing ₡ 20,000 (about $35) and a cellular phone from another customer.

The three men escaped in a white car with black stripes. As of 2:30 p.m. Monday, the National Police and the Judicial Investigation Police (OIJ) had no clues to the suspects' identities or whereabouts.

Librería Lehmann is one of Costa Rica's largest book retailers with stores in downtown San José, San Pedro, east of San José, Rhormoser, west of San José, and Tibás, north of the capital city. The chain was founded in 1896.