The gunman who killed 10 people at a school in Sweden was a reclusive, unemployed man who legally owned firearms and had no criminal record, according to reports.

Swedish media named Rickard Andersson as the person behind Tuesday’s attack – in what was the largest mass shooting in the country’s history.

The 35-year-old, who died at the scene from an apparent self-inflicted gunshot wound, had distanced himself from family and friends in recent years, relatives said as details about him began to emerge.

Police raided his home in Orebro following the shooting at Campus Risbergska on the outskirts of the city, TV4 television reported.

Orebro police chief Roberto Eid Forest confirmed on Wednesday that evidence suggested the gunman took his own life and was already dead when officers arrived at the scene.

Andersson reportedly changed into a military uniform in the school’s bathroom before he opened fire.

One police theory is that he deliberately spared some people while targeting others, although his reasons for doing so remain unclear, according to Aftonbladet, a Swedish newspaper.

Students at the school described scenes of chaos, with people running through corridors while the gunman calmly walked around and fired his weapon.