A person believed to be the gunman who shot dead 10 people including himself in a rampage in Munich said in a mobile- phone video aired by the media that he had been hospitalized for psychiatric problems.
Police said they are trying to verify the footage, which appeared on 24-hour news channel NTV.
"I was hospitalized for psychiatric problems," he says in a video filmed by a nearby resident.
"I am a German," the man is also held saying. "I was born in Germany."
There has been some backlash from right-wing groups against the high number of migrants who have entered Germany in recent months and the country has been on high alert since Monday, when an Islamist asylum seeker injured five people in a knife-and-axe attack on a commuter train.
The authorities believe he acted alone in the shooting spree, which began shortly before 6 pm local time (16:00 GMT) and which led to panic among shoppers and workers.
In other videos that have surfaced since the attack, people can be heard shouting and screaming as they fled the shopping centre.