A man has been charged with the murders of Zoe Morgan, 21 and Lee Simmons, 33, who were stabbed to death in Queen Street in Cardiff on Wednesday.
Andrew Patrick Saunders, 20 is accused of killing the two Matalan employees, and will appear before magistrates on Friday, South Wales Police said.
The bodies of shop assistant Mr Simmons and window dresser Miss Morgan, were found at 5.50am on Wednesday.
More than a day on from the deaths, there was still a sense of disbelief and shock that a young couple could lose their lives on one of Britain's busiest shopping streets.
Matalan staff in Cardiff, back at the Queen Street store for the first time since the tragedy, held a tearful staff meeting before bosses decided to remain closed for another day.
Workers struggled to fight back tears as they looked at the tributes left for the couple outside the store.
One read: "Lee and Zoe, you will be missed dearly. Rest in peace."
Miss Morgan's family issued a tribute to her, saying she was a "beautiful daughter, sister, granddaughter and auntie who had a heart of gold and would do anything for anybody."
They added: "She was taken away from us tragically, too soon, and has left a massive hole in our lives that will never be filled. Zoe will always be in our hearts forever and always. We are all broken hearted."
It is believed that Miss Morgan and Mr Simmons had been together for four months, having struck up a romance while working together.
Detective Superintendent Ceri Hughes said: "What happened to Zoe and Lee is an absolute tragedy. Their families are devastated. Our thoughts remain with them. This has shocked the community of Cardiff.
"We are very conscious that people who witnessed the incident may be traumatised. We can signpost those affected to a range of support services."