MIAMI (CBSMiami/CNN) – A Chinese man who was arrested for allegedly entering a restricted area on a Naval base in Key West and taking photos 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.

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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.

A Mandarin interpreter was present in court. The next court date on the case has not been set.

Beijing working to ‘steal American secrets’

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US officials, analysts and experts have previously told CNN that Beijing is working to undermine American industries, steal American secrets and eventually diminish American influence in the world so that the Chinese government can advance its own agenda.

The Chinese government has repeatedly said it is acting in good faith in its interactions with the US. “I do not know where this strong sense of insecurity comes from,” Foreign Ministry spokesman Geng Shuang said earlier this year.

Last year, two Chinese Embassy officials were “secretly expelled” by the US after they entered a “sensitive” military base near Norfolk, Virginia, according to The New York Times.

The Times said half a dozen people with knowledge of the expulsions said US officials believe “at least one of the Chinese officials, who were with their wives, was an intelligence officer operating under diplomatic cover.”

In February, a 20-year-old Chinese student was sentenced to a year in federal prison after he pleaded guilty to illegally taking pictures at the Joint Interagency Task Force South military property, also located on Naval Air Station Key West.

Additionally, a Chinese woman was arrested earlier this month and charged with trespassing on President Donald Trump’s Mar-a-Lago property, according to Palm Beach Police — the second time this year that a Chinese national has been arrested for intruding on the President’s Florida property.

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