Melinda Vinalis, a work colleague of British football coach Mike Jones, told ITV1's Daybreak: "I couldn't imagine his last moments, that was hard for me. How much he suffered and that he was alone."
More top news
The slump will spark scrutiny, especially as statistics show a rise in racially or religiously motivated offences following the EU vote.
The 53-year-old was killed shortly after leaving her home in Mosta, Prime Minister Joseph Muscat said.
Jordi Sanchez of the Catalan National Assembly and Jordi Cuixart of the Omnium Cultural group were jailed on Monday.