Bonsoir
pour mettre à la voix passive, tu dois utiliser BE au temps correspondant de la voix active + participe passé de la Base verbale
A man was found dead in Mrs. Marsden's garden this morning. He was given missing by his wife, Mrs. Roberts on Tuesday.
Detective Leek thinks it was an accident : "The dead man was killed by a flowerpot. It was probably hit by a cat. Mrs. Roberts and her children were reported the sad news by Mrs Madsen."
Bonne soirée☺☺☺