German police have denied earlier assumption that the 17-year-old gunman who killed 15 people and himself Wednesday at a German school had talked about his plan in an Internet chat room.
A local police spokesperson said late Thursday evening that the previous assumption of the investigators turned out to be wrong, local media reported.
Earlier, Heribet Recht, interior minister of Baden Wuertemberg, said the teenager gunman had announced on the internet that he planned to "fry" his former school with his weapon because people did not take him seriously, Xinhua reported.
Now police have found out that the posting was not written on the computer of the teenager and was possibly written by someone else after the shooting, German newspaper Sueddeutsche Zeitung reported.
Local police and the Public Prosecution Service of Stuttgart said they will hear the witnesses who claimed to have seen the posting but the key question would be when the message was posted.
The authorities also noted that they had asked the operator of the server in the United States for help in the investigation.
The chatroom website itself, www.krautchan.net, is currently not available, allegedly because of its limited capacity to handle the current rush.
One day after the school shooting, German police received several bomb and rampage threats which were also targeted at schools.
According to Erwin Hetger, Baden Wuertemberg state's police chief, schools in southwestern cities of Pforzheim, Stuttgart, Ulm, Freiburg, Metzingen and Esslingen are under heavy police observation.
On Thursday, a 22-year-old student was arrested by police and given a suspended sentence of five months in prison for threatening rampage at his vocational school in the eastern German city of Halberstadt.
The man's motive was to cancel classes under the assumption that the school would close under police operation. He found himself in the court only seven hours after he made the threat phone call, Spiegel online reported.
A district court of Berlin on Thursday sentenced a 21-year-old to one week's detention. The man confessed that he threatened violence on a social network site on the Internet in spring 2008.