LAWRENCEVILLE, GA. — Federal authorities have begun deportation proceedings against an 85-year-old suburban Atlanta man who they say served as a Nazi guard and trained and handled attack dogs at the Dachau and Buchenwald concentration camps.

The Department of Justice and Department of Homeland Security allege Paul Henss, a German citizen who lives in Lawrenceville, about 30 miles northeast of Atlanta, entered America in 1955 after hiding his concentration camp service.

The Department of Justice announced the action against Mr. Henss yesterday; federal authorities filed an immigration document making the allegations September 4. Yesterday, in his driveway in a tidy, middle-class neighborhood where the streets are named after tennis stars, Mr. Henss said he had been an SS soldier and had trained German shepherds and Rottweilers during World War II, but he angrily denied being a war criminal.

“I didn’t commit no crimes,” Mr. Henss said in a thick German accent. “I didn’t hurt nobody. Otherwise, I wouldn’t have come to the United States.”

Mr. Henss called the Holocaust “a catastrophe” and said: “Everybody in Germany knows that wasn’t right.”

According to federal authorities, Mr. Henss joined the Hitler Youth organization in Germany in 1934 as a 12- or 13-year-old boy and joined the Nazi Party in 1940.

He entered the Waffen SS in 1941 and volunteered the following year to become an SS dog handler, serving between 1942 and 1944 at the Dachau and Buchenwald concentration camps in Germany, the immigration document states.

There, Mr. Henss instructed other guards in the use of trained attack dogs to guard prisoners and prevent their escape, and personally guarded prisoners and forced-labor details to prevent escapes, authorities allege. SS regulations during Mr. Henss’s time of service said dogs were to be trained “to ‘bite without mercy’ and to literally tear prisoners to pieces if they attempted to escape,” the document states.

Mr. Henss acknowledged in a sworn statement on March 13 that he served as an SS guard at Dachau and Buchenwald for two to three months each as a dog handler, according to the charging document.

Yesterday, he acknowledged training dogs but said he fought in Russia and never set foot inside Dachau or Buchenwald.

“The training of dogs was no crime,” Mr. Henss said with his wife sobbing next to him outside their well-kept one-story brick house. “I was not training them to hurt people.”

Mr. Henss said that when he came to America 33 years ago, he did not tell immigration officials about his military service in Germany and was not asked.