The police work of tracking down suspected homosexuals depended largely on denunciations from ordinary citizens. Nazi propaganda that labeled homosexuals "antisocial parasites" and "enemies of the state" inflamed already existing prejudices. Citizens turned in men, often on the flimsiest evidence, for as many reasons as there were denunciations. Reflecting on the dramatic rise of legal proceedings against homosexuals since 1933, Josef Meisinger of the Reich Central Office for Combating Homosexuality and Abortion proudly remarked in April 1937: "We must naturally also take into account the greater public readiness to report [homosexuality] as a result of National Socialist education."

Acting on the basis of these informants, the Gestapo and Criminal Police arbitrarily seized and questioned suspects as well as possible corroborating witnesses. Those denounced were often forced to give up names of friends and acquaintances, thereby becoming informants themselves. Where criminal proceedings once required a proved act, now a suggestive accusation sufficed.

During the Nazi era, some 100,000 men were arrested on violations of Paragraph 175. Of these, nearly 78,000 were arrested during the three years between Heinrich Himmler's appointment as chief of German police in 1936 and the outbreak of World War II in 1939. The Gestapo and Criminal Police worked in tandem, occasionally in massive sweeps but more often as follow–up to individual denunciations.

Most victims were from the working class. Less able to afford private apartments or homes, they found partners in semi–public places that put them at greater risk of discovery, including by police entrapment.

As reports of the massive arrests spread, mostly by word of mouth, a pervasive atmosphere of fear enveloped Germany's homosexuals. Just as the state desired, the physical repression of a minority of homosexual men served to limit activities of the vast majority.

Of the estimated 100,000 men arrested under Paragraph 175 between 1933 and 1945, half were convicted of violating the law. Just as arrests rose precipitously after the 1935 revision of Paragraph 175, so, too, did conviction rates, reaching more than ten times those of the last years of the Weimar Republic and peaking at more than 8,500 in 1938. Prison sentences, the most common punishment in the Nazi persecution of homosexuals, varied with the sexual act involved and the individual's prior history.

For many, imprisonment meant hard labor, part of the Nazi "re–education" program. Conditions in German prisons, penitentiaries, and penal camps were notoriously wretched, and those incarcerated under Paragraph 175 faced both the brutality of the guards and the hatred of their fellow inmates.

In a small number of cases, medical experts testified that some homosexuality constituted a serious mental illness and danger to society. Under Paragraph 42b of the Reich Criminal Code, some men were institutionalized, a fate that could have disastrous consequences (including death) during the war.

Identification pictures of a bartender from Duisburg who was arrested for homosexuality. Duisburg, Germany, August 27, 1936.

A writer from Düsseldorf who was arrested for homosexuality. Düsseldorf, Germany, 1938.