The family of Sarah Everard have said they are haunted by thoughts of her suffering in the final hours of her life when she was raped and murdered by a police officer, in emotional victim impact statements read in court.

Wayne Couzens seized Everard, 33, from a London street on 3 March, keeping her captive using his police handcuffs before strangling her with his police belt and then burning her body.

On Wednesday, the first day of Couzens’s sentencing hearing at the Old Bailey in central London, Everard’s parents and sister described the multiple agonies they endured, first not knowing where she was when she disappeared, and then waiting to find out how she had died and being unable to say goodbye because her body had been burned.

Everard’s mother, Susan, said: “In her last hours she was faced with brutality and terror, alone with someone intent on doing her harm. The thought of it is unbearable. I am haunted by the horror of it.

“I am repulsed by the thought of Wayne Couzens and what he did to Sarah. I am outraged that he masqueraded as a policeman in order to get what he wanted. Sarah wanted to get married and have children; now all that has gone. He took her life and stole her future and we will never have the joy of sharing that future with her.”

She said alongside the sorrow came “waves of panic” at not being able to see her youngest child again. She said the family had kept their daughter’s dressing gown because “it still smells of her and I hug that instead of her”.

She said Couzens’ cruelty was incomprehensible. Faltering briefly, she added: “In the evenings, at the time she was abducted, I let out a silent scream: don’t get in the car, Sarah. Don’t believe him. Run!”

Jeremy Everard and the couple’s other daughter, Katie, each asked that Couzens face them before they began addressing him directly. In both instances, Couzens, who sat throughout the hearing with head bowed and eyes closed, lifted his head slightly but did not look at them.

Jeremy Everard said: “Sarah was handcuffed and unable to defend herself. This preys on my mind all the time. I can never forgive you for what you have done, for taking Sarah away from us. You burned our daughter’s body, you further tortured us, so that we could not see her again. We did not know whether you had burned her alive or dead. You stopped us seeing Sarah for one last time and stopped me from giving my daughter one last kiss goodbye.”

Katie Everard said she had been shocked by Couzens’ “casual demeanour” on CCTV as he bought a drink at a petrol station at a time when her sister was probably already dead.

Weeping, she told him: “It disgusts me that you were the last person to touch her perfect body and violate her in the way you did. The last person to see her alive and speak to her. How scared she must have been. The last moments of her life not with loved ones, but frightened and fighting for her life.”

She said no punishment received by Couzens could ever compare to the pain suffered by her family, describing her sister as “the very best person with so many people who love and cherish her”.

Susan Everard said Sarah was caring, funny and strongly principled. “What I do know is that Sarah will never be forgotten and is remembered with boundless love,” she said.