STATEN ISLAND, N.Y. -- In 1938, Ernest Lehmitz -- a German-American -- traveled back to his home country to visit family.

He would return to the United States in 1941 as a spy.

The Staten Island resident, who was arrested 75 years ago last month, was involved in one of the largest espionage cases in United States history at the time, and a story so captivating that it seems almost too good to be true.

Lehmitz became a citizen in 1924 and purchased an all-brick house on Oxford Place in Tompkinsville.

He worked as an air-warden and as a porter at Cuff's Restaurant in Port Richmond during his time on Staten Island -- jobs that would aid in his mission of espionage.

His accomplice, Erwin DeSpretter, who was a former lieutenant in the German army during World War I, lived in Dongan Hills, according to Advance archives.

Their inconspicuous nature would aid them in avoiding detection for some time.

Lehmitz was especially cunning. He would later state that he volunteered as an air raid warden to help "protect" his neighbors from enemy attack, according to Advance archives, in an effort to appear supporting to the American cause.

His intentions, however, were far more sinister.

Rob Weingartner, a Staten Island resident fascinated by World War II, has been researching their story. Interested since the moment he heard about the arrest, Weingartner filed a Freedom of Information Act request with the FBI and began receiving hundreds of previously classified files regarding the case. With every new page, Weingartner said he was more and more fascinated.

"The more I started to research, the more I started to find out," he said.

THE CASE

Weingartner said, through his reading of the files, that along with the FBI, British Intelligence and the War Department were involved in searching for Lehmitz and DeSpretter, after it was discovered that they were sending troop and ship locations to anonymous sources in neutral European countries to later be filtered to Germany. That information was then passed on to German U-boat commanders operating in the Atlantic Ocean.

However, while the letters were eventually discovered, Weingartner said that there was over a dozen that were not intercepted due to Lehmitz's ingenuity.

"They found his letters and realized there was invisible ink on them," Weingartner said.

In between mostly innocuous typed lines of text, Lehmitz hand-wrote, in German, detailed information about U.S. military ship positions in New York Harbor and created over a half-dozen aliases to avoid detection -- the most common being "Fred Lewis" -- which led the FBI to name his case the "Fred Lewis" case, since they believed, at one point, that there was a possibility that was the author's real name.

One letter, according to Advance archives, read, "Eleven ships leaving for Russia, including steamer with airplane motors and 28 long-range guns. One steamer has deckload of airplanes, below deck airplane motors, Boeing and Douglas airplane parts on steamer with Curtiss-Wright airplanes, motors and small munitions, searchlights and telegraphic material."

Lehmitz numbered the letters to his European cohorts, and while letters 15-26 were confiscated by British Intelligence in Bermuda between late-1941 and early-1942 -- where all air mail had to be transported before making its way to Europe -- Weingartner said that letters 1-14 were never found.

To gather information, Lehmitz housed troops, a popular practice at the time, and listened in on conversations on Richmond Terrace, which was once a bustling industrial area containing thousands of dockworkers, troops and sailors.

Lehmitz made a habit of listenening in on conversations that loose-lipped sailors were having at bars in the area. Any information he picked up would later be included in his letters to his European cohorts, according to Advance archives.

DeSpretter also held degrees from two different German institutions and possessed technical expertise, giving him the skillset to aid Lehmitz in his spy duties.

THE TYPEWRITER

The FBI worked diligently to locate Lehmitz and DeSpretter.

According to Weingartner, once British Intelligence Agencies passed over the intercepted information to the FBI, they began by confirming that all of the letters contained identical handwriting by consulting with a handwriting expert.

Next, the FBI worked to confirm which kind of typewriter Lehmitz was typing the faux-letters on to conceal his hidden messages.

Once found, FBI agents began a tedious process of locating the stores that sold the typewriter in New York and then received lists of everyone who had bought that typewriter in a recent time frame.

However, that list, as one might imagine, was exhaustive, and Weingartner said that "they were investigating people all across the U.S."

The FBI later discovered that the previously-thought "filler" information contained in the letters actually held shreds of truth. Lehmitz wrote about having a victory garden in his backyard, and renting out housing for military members, according to Advance archives. In one letter that was intercepted by British Imperial Censors in Bermuda in 1942, Lehmitz mentioned that he arrived in New York from Lisbon, Portugal, from a vacation about a year before in 1941 -- the piece of information that helped close the case.

THE MISSING LINK

The FBI scoured a NYC port, going through records of luggage placed on ships that arrived from Portugal in the spring of 1941.

After painstakingly going through pages of signatures by passengers, the FBI found a handwriting match and name on a baggage check slip belonging to Lehmitz - it was the final piece of the puzzle.

In late June of 1943, Lehmitz did not show up for his job at Cuff's. He was arrested and in federal custody, and the following day stood before a U.S. commissioner in Brooklyn and pleaded guilty to espionage.

Lehmitz was sentenced to 30 years in prison, and DeSpretter, who was also busted in the case for helping supply Lehmitz with additonal information, was deported in 1955, since he was never an American citizen.

A CLOUDY ENDING

After the case closed, Lehmitz's story gets cloudy.

According to Weingartner, Lehmitz was given parole and died on Staten Island in 1967.

Clad in mystery following his parole, he was buried in St. Peter's Cemetery on Clove Road under an untitled grave, according to cemetery records.

Seventy-five years after this landmark case drew to a close, Lehmitz's story remains a significant and largely-untold espionage bust during one of the most tumultuous periods in the country's history - nearly forgotten in Staten Island's lore.

Robert Weingartner is in the process of writing a book regarding the case. Any readers with stories or information regarding Lehmitz or DeSpretter are encouraged to contact Robert Weingartner via email at robjwein@gmail.com.