Bush, of Otley, West Yorkshire, was arrested when he landed at Heathrow Airport days later.
He told officers his daughter, with whom he was travelling, was “unaware” of what had happened and said, “I have deceived everyone”.
Of the remains discovered at the Hessle Road premises, most were “of older people above the age of 60” and about six bodies were waiting to be cremated.
One of the bodies had been at the site for a year.
Hundreds of victim impact statements are expected to be read over the course of the week.
The first was from Karen King, whose father Norman Bridger’s body was recovered 10 months after his death, which described how she had lockets made for her and her mother containing the ashes given to her by Bush.
“I now feel violated that I have had some unknown person’s ashes so close to me,” she wrote.
Kathryn Howard, who used Legacy after her 73-year-old partner Jonathan Butler died, told the court her “world fell apart all over again” when she learned his body had been left at the site.
She said an apology “would not be enough for me” and wanted Bush to know that she will “never, ever, get over this”.
