Massimo Dallamano's 1975 giallo, What Have They Done to Solange, takes its influence from the German crime genre known as krimi. German film producers had been adapting the novels of British author Edgar Wallace since the 20's but it was the Danish company, Rialto Film, who acquired exclusive rights to most of Wallace's novels in the early 60's. The original krimis were black and white but Rialto introduced color to the genre and and opted for stylish over substantial reimaginings of the Wallace novels. Rialto ignored the actual narrative of his stories and decided to hone in on the motives behind the murder mysteries. This explains the reason why Dallamano's film doesn't quite connect with Wallace's novel, The Secret of the Green Pin, also known as The Clue of the New Pin or Das Geheimnis der grünen Stecknadel. Solange was released under this title as well in the US and West Germany but the book and film have little in common aside from a few details, most notably the mention of a green stick pin. As the quality of the Rialto films took a nose dive in the late 60's, the company reached out to Italian producers to form four co-production companies to keep their costs low. Thus began one of the initial influences for giallo, aside from the yellow paperbacks where the genre gets its name. Similarly, the krimi films were also an influence on the Italian tough-cop genre know as polizotteschi. Shared traits between the three include uber violence, corruption and the investigation/investigator as a main focal point.