A MURDER suspect poisoned his victims with lethal "quadrupole" dosages of drugs he concocted in his own home, a court has heard.

Luke D’Wit, who is standing trial for the murder of Carol and Stephen Baxter, is accused of replacing the Baxters’ medication with identical pills filled with a deadly concoction of promethazine and Fentanyl, which D’Wit had created himself using a makeshift pestle and mortar.

A coroner later ruled that Mrs Baxter, 64, had died as a result of combined fentanyl and promethazine toxicity with terminal bronchopneumonia.

Mr Baxter’s death was caused by alcoholic liver disease with fentanyl intoxication, the coroner ruled.

Gazette: Luke D'Wit is accused of murdering the Baxters and re-writing their will

Tracy Ayling KC, prosecuting, asserted the pills the Baxters ingested were identical to those found in D’Wit’s address when it was searched by police.

She said: “Pills had been replaced with pills which were four times the dosage of promethazine.

“A makeshift mortar and pestle was found at the home address of the defendant.”

The court was then shown a picture of the makeshift pestle and mortar D’Wit is said to have used to create the promethazine dosage.

Mrs Ayling continued: “The tablets found in the defendant’s bag under his desk when he was arrested are identical to the crushed-up matter in the pot.”

The prosecution told the court how ring doorbell footage showed D’Wit knocking on his neighbours a week after the Baxters had been murdered, asking for CCTV footage of the Baxters’ address.

D’Wit had claimed he wanted to see the footage because he had been expecting a delivery at the address that hadn’t arrived.

Mrs Aying said: “You may wish to ask yourselves why D’Wit was so anxious about CCTV facing the Baxters’ front door.

“As a result of those things, D’Wit was a suspect and was arrested on July 6.”