The Lawerence Berkeley Hack, Part 2

Oמ May 23rd, 1989, Karl Koch - a 23 years old West German hacker who worked for the KGB -  took a drive, from which he would never return: Nine days later his charred remains were found by the police in a remote forest. Was Koch assasinated by the US or the Sovient Union, or is there another, more 'mystical' explanation for his death?