Corder was given the chance to confess in court, but maintained he was innocent.

Some people still believe that he did not commit the murder, and was wrongly convicted. Documents in his own hand prepared for his trial (now in private possession) show that this was not so. At one point the text has been crossed out and the story changed: the original version exposed his guilt. At half past eleven on the night before he was to hang, Corder at last confessed. He said that he and Maria had quarrelled about the burial of their child and other matters. A scuffle broke out, he took his pistol from his jacket pocket and fired. Maria fell dead. He denied utterly that he had stabbed her. However, it was felt by many that this was only a partial confession. Corder, true to his nature, kept the full story to himself to the very end.

Several arguments have been put forward in Corder's defence:

• He was not the monster which myth supposed him to be. After all, he stood by Maria when she fell pregnant with his child;
• adverse press coverage before the trial was prejudicial to a fair outcome;
• the trial, sentence and execution were driven by press interest;
• the evidence against him was all circumstantial, and the trial was a travesty. Mistakes were made and witnesses manipulated; and
• Ann Marten (Maria's stepmother) was involved and made up the story of the dream to ease a guilty conscience. It has even been suggested that Ann was having an affair with Corder, that Maria found out, caused difficulty, and had to be stopped. Certainly circumstantial evidence could be made to support this view: the dreams started in mid December 1827,a few days after Corder married Mary Moore. It would probably have taken news of the marriage that long to reach Polstead. Was the dream a coincidence? Could it have been the reaction of a woman scorned?