The student who opened fire at a university in Prague, killing at least 14, is also suspected of killing another man and his newborn baby last week.
The gunman killed 14 people and injured 25 during a rampage at Charles University in Prague on Thursday.
He was shot dead after carrying out the horrific attack, the Czech Republic's worst mass shooting. His name has not been officially released but he has been named by media outlets as 24-year-old David Kozak.
Prague Police Chief Martin Vondrasek said police believe the gunman killed his father earlier on Thursday in his hometown of Hostoun, just west of Prague, and that he had also been planning to kill himself.
Police gave no details about a possible motive for the shooting at the building located near the Vltava River in Jan Palach Square, a busy area in the heavily-visited Old Town.
Officers have also linked him to the killing of another man and his two-month-old daughter on December 15 in Klanovice, near Prague.
More than 250 police were sent to search the area and a helicopter with thermal imaging was used to scour the woodland area, but the gunman in that case was never found.
The gunman suffered “devastating injuries" but it wasn't clear if he killed himself or was shot to death in an exchange of gunfire with officers, Mr Vondrasek said, adding that there was "nothing to suggest that he had an accomplice."
The heavily-armed shooter legally owned several guns.
“We mourn the loss of life of members of our university community, express our deepest condolences to all the bereaved and our thoughts are with all those affected by the tragedy," Charles University said in a statement.
The government quickly sought to quell concerns that the massacre was backed by foreign interests, saying there was no indication it was a terror attack planned abroad.
Authorities evacuated everyone from the building and police said they were still searching the area, including the balcony, for explosives.
The Czech government declared Saturday a national day of mourning to honour the shooting victims, Prime Minister Petr Fiala said.
Some video footage showed people being evacuated from the building and others trying to hide behind a wall.
Ivo Havranek, a diving instructor, said he was near the building when he heard a shot ring out, but he didn't quite believe that was what he had heard.
"Only at the moment when I saw the fully equipped riot police with bulletproof vests and shields, it looked to me that I had found myself in a movie," Mr Havranek said. "But it was obvious that nobody was shooting a movie."
