While cleaning my old bookshelf I came across one of the very first books I ever read about the Third Reich, the "Die Reichskanzlei von 1933-1945, Anfang und Ende Des Dritten Reiches" by H.S. Hegner (a Finnish translation, dated 1960). Out of curiosity I checked the chapter dealing with the Night of the long knives and besides the usual narrative there were many interesting details that had not been repeated in most of the later works.
First, a certain SS-Sturmführer Solm is mentioned in connection with the murder of ex-chancellor, general Kurt von Schleicher. He was said to have been in good terms with the Reichswehr senior officer corps and in the morning of June 30th, he apparently went to see the duty officer in the Bendlerblock to tell what he knew about the murder plot. He, Solm, was then sent to von Schleicher's house in Neubabelsberg. While on his way, his car was passed by another, carrying 5 "SS men" who also were enroute to the same destination.
Solm reportedly crashed on his way and never managed to reach von Schleicher. Later, a group of detectives sent by Göring (to arrest von Schleicher) passed the crash scene. On their arrival, von Schleicher and his wife had already been shot. Frau von Schleicher was still alive and a doctor was summoned but he was unable to aid her anymore. A crime scene investigation was ordered by these men. Later on the same day, the house was thoroughly searched by a group of Gestapo men confiscating every aggravating document they could found. In addition to all this, Hegner writes that the doctor who was one of the first witnesses of the murder scene, Dr. Schulz, died mysteriously only couple of months later.
The book is not written in a scholarly way and there are numerous errors, especially with the details. I was not able to find any reference to SS-Sturmführer Solm from DAL-1934 nor from anywhere else. The highly detailed (and dramatized!) style of description suggests that it was based on post-war testimonies and/or memoirs of various witnesses. It is also highly possible that Hegner had simply filled the gaps in the story with assumptions and imagination.
This description of events awakes three questions:
1) Who - if he existed at all - was this mysterious Sturmführer Solm? How could he have learned of the supposedly top-secret plans to eliminate von Schleicher?
2) Hegner suggests that the murderers of von Schleicher were sent by Heydrich after the order received from Himmler. If this was the case, it seems strange and contradictory that Göring (who - according to all accounts - was most of the time present in the same rooms with Himmler) decided to send another squad to simply arrest him. In June-July 1934, Göring was still the titular head of the Prussian Gestapo. Why did he choose a Kripo squad for the purpose? That it was a Kripo squad is only my educated guess, since Hegner refers to it as a "group of detectives", the wording which he does not employ when meaning Gestapo officials.
3) Even more strange is the course of action. First, a group of 5 Gestapo/SS men entering von Schleicher's house displaying a badge of authority (which must mean the first pattern Gestapo warrant disc), followed by an outright murder of the general and his wife. Then, the arrival of the Kripo men who might not have been aware that the execution had been ordered from above and treated the case as a murder case. Although Hegner does not specifically mention that the investigation was ceased, that must have happened since the Gestapo had a free hand to make a house search only few hours later.