(CNN) A Chinese national arrested for allegedly entering a restricted area on a Naval base in Key West and taking photos of government buildings pleaded not guilty to the charges against him in federal court Monday, according to his attorney Daniel Rashbaum.

Liao Lyuyou, 27, was indicted on three counts of photographing and sketching defense installations and one count of entering military, naval or Coast Guard property, according to court documents.

His arraignment lasted about 15 seconds, Rashbaum said.

Naval officials arrested Liao at the Naval Air Station Key West on December 26, after court documents say he circumvented a security fence with "numerous warnings posted" and took photos. Liao told officers he was trying to take pictures of the sunrise and gave them permission to look at his camera, where they found images of the Truman Annex as well as other government buildings in the area.

The charges against Liao are all misdemeanors. The photographing charge carries a maximum penalty of one year in prison while the charge relating to entering the facility carries a maximum of six months in prison, according to court documents.