His run-ins with the law regarded threats, property damage, fraud and a hit-and-run, but Ms Adomeit said all charges were dismissed.
However, investigators found no signs of a political motive in their initial searches of the apartments and of several cars and a container belonging to the man, Kuhlisch said.
But authorities appeared near-certain that there was no Islamist connection to the violence in the historic center of Muenster.
"With dismay, I learned of the awful incident in Muenster", Seehofer said in a statement Saturday, adding, "Police in Muenster and throughout (the state of North Rhine-Westphalia) are now working hard to investigate the matter". He then took his own life with a gun.
The German news agency dpa is quoting police as saying that that the driver who crashed his van into a crowd in the western German city of Muenster had no accomplices. The perpetrator killed himself upon performing the attack.
As per a Reuters report, the vehicle ploughed into people seated at tables outside the Grosser Kiepenkerl eatery, a popular destination for tourists in the city's old town, killing a 51-year-old woman from Lueneburg and a 65-year-old man from Borken.
The driver of the van was not identified by name.
Police said it was too early to speculate about the motive behind the crash and say they are still investigating.More news: India, Nepal to build trust; announce joint initiatives in key areas
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The daily Sueddeutsche Zeitung said police had found an 18-page missive in his Pirna home in which he wrote of his anguish due to serious problems with his parents, "repeated nervous breakdowns" and "explosions of aggression" as well as a botched medical operation.
Seehofer was speaking in Muenster, where a man drove a camper van into a group of people sitting outside a restaurant on Saturday, killing two of them before shooting himself dead.
"So far there are no indications of a possible background for the crime", senior public prosecutor Martin Botzenhardt said in a joint statement with Muenster police.
Reul added: "we are investigating in all directions".
Earlier today, Interior Minister Horst Seehofer said the government would do everything possible to protect citizens, but added: "We have again experienced that. absolute security is unfortunately not possible".
The attacker had vaguely announced his suicide plans a week ago in an email to friends, it is claimed, but police would not confirm this.
The foreign ministry in the Netherlands said two of the injured were Dutch, one of whom was in a critical condition.