A man who shot dead seven people in Germany was visited by police last month after a tip-off raised concerns about his mental health.
He co-operated with officers and there were not enough grounds to take away his gun at the time, police said.
The 35-year-old suspect, named only as Philipp F, had a licence to own the weapon for sporting purposes.
The country is preparing a new law involving tighter curbs on gun ownership, the interior minister said.
Seven people, including an unborn baby, were killed in Thursday’s attack which unfolded at a Jehovah’s Witness meeting hall in the city.
The first emergency call came at 21:04 local time (20:04 GMT) to report that shots had been fired, and officers were on site four minutes later.
Video appeared to show the gunman firing through a window. He then stormed the building where dozens of people had gathered, firing nine magazines of ammunition before apparently turning the gun on himself after police arrived.
Eight people were injured, including a woman who was seven months pregnant. She survived but her unborn baby was killed.
Chancellor Olaf Scholz said the death toll could rise.
(BBC News
