According to Another Monster, he was the lieutenant of a prominent figure in organized crime and protected the syndicate's assets. At one point, under his auspices, the syndicate invested their funds in an underground banking organization that facilitated money laundering. However, upon hearing rumors about the underground bank (secretly run by Johan Liebert), he insisted that the syndicate withdraw its assets, which he proceeded to do shortly before it imploded into management chaos and betrayal. Later, after most of his family disowned him due to the nature of his business and his superior attempted to have him assassinated due to facilitating financial transfers with a rival syndicate, he went into hiding near Füssen at a mountaintop enclave.
There, he sought medical attention from Dr. Kenzo Tenma, who was working as a black market doctor at the time, and happened to be accompanied by Dieter and Otto Heckel. Heckel introduced him to his recipe for chicken marengo (Napoleon's favorite dish) at lunchtime, and he found the meal to be quite delicious as the four ate outside together. He finally relented to having his bodyguard share a meal with them, in spite of his duties to guard the only accessible path to the villa. Dieter went down the mountain to retrieve him, but instead found Eva Heinemann, accompanied by Roberto, both of whom had come seeking Tenma, knowing of Heitmeyer's location and his connection to him. However, Eva had no intentions of seeing her former fiancee dead, in spite of her animosities, and was wounded in the leg by Roberto.
Luckily, she was treated by Tenma after Dieter stayed by her side and, afterwards, she was left in Heitmeyer's custody. When she regained consciousness, he took care of her and they shared a lunch of chicken marengo in the preceding period, with him commenting on how lucky she was and what a beautiful day she had lived to see.
He was interviewed by Werner Weber, under the condition his real name not be used.
(Source: Monster Wiki)
