Soon after the explosion, suspicion fell upon Michael Kristoff, a Slovak immigrant. Kristoff would later serve in the United States Army in World War I, but admitted to working for German agents (transporting suitcases) in 1915 and 1916 while the US was still neutral. According to Kristoff, two of the guards at Black Tom were German agents. It is likely that the bombing involved some of the techniques developed by German agents working for German ambassador Count Johann Heinrich von Bernstorff and German Naval Intelligence officer Franz von Rintelen, using the cigar bombs developed by Dr. Walter Scheele. Captain Franz Von Rintelen used many resources at his disposal, including a large amount of money. Captain Franz von Rintelen used these resources to make generous cash bribes, one of which was notably given to Michael Kristoff in exchange for access to the pier. Suspicion at the time fell solely on German saboteurs such as Kurt Jahnke and his assistant Lothar Witzke, who are still judged as legally responsible. It is also believed that Michael Kristoff was responsible for planting and initiating the incendiary devices that led to the explosions.