Brothers killed woman with chloroform on Christmas Eve
A "callous and calculating" cash-and-carry worker and his brother have been found guilty of murdering a marketing manager who was smothered with chloroform on Christmas Eve.
Costco store boss Roger Cooper and ex-soldier David Cooper bought poisonous metals, identified a shallow grave and communicated in text messages written in a Star Wars-based code before killing Sameena Imam.
An eight-week trial heard that Roger Cooper spent at least a month plotting to kill the 34-year-old - one of his three lovers - to prevent her exposing their two-year affair.
Both Roger and David Cooper - who are 6ft 5ins and 6ft 7ins tall - remained calm and did not look at each other as they were unanimously convicted by a jury at Birmingham Crown Court.
Miss Imam, who was just 5ft 2ins, is believed to have been overpowered on a sofa at David Cooper's home in Hughenden Drive, Leicester, between 5.07pm and 6.26pm on Christmas Eve after being driven to the property from Coventry by his brother.
The victim, who worked at Costco stores in Cardiff, Southampton, Bristol and Coventry, was reported missing by family members in Essex after failing to return home for Christmas, sparking a major police inquiry.
Roger Cooper, 41, and his 39-year-old brother were arrested on suspicion of murder on January 7 - a week before Ms Imam's body was found buried on an allotment in Leicester.
Post-mortem tests established that the shop worker, who lived in Cardiff, was killed using chloroform.
A "bizarre" combination of metallic elements, including antimony, cadmium, tin, mercury and arsenic, is also thought to have been administered to Ms Imam in a liquid.
At the start of the trial, it was alleged that Roger Cooper was "juggling" relationships with three women, including Sameena and a second colleague, while managing Coventry's Costco warehouse.
The retail worker, of Tilehurst Drive, Coventry, told police investigating Miss Imam's disappearance that he last saw her when she left the store at about 4pm on December 24.
His brother told officers he did not even know Miss Imam's name but later made a partial confession, claiming to have pressed a chloroform-soaked tea towel over her mouth.
Although the former signals regiment reservist claimed the death had been an accident, he later changed his account, telling jurors he found Ms Imam's body after being asked to move a car.
But messages sent from a mobile phone linked to David Cooper - including Stars Wars-related phrases such as "Death Star complete", "stay on target" and "look at the size of that thing" - proved the brothers had made a previous attempt on Ms Imam's life in mid-December.
Roger Cooper admitted in court that a message reading "You are expected Vader" was a coded reference to Miss Imam but insisted it had been part of surveillance to check if she was seeing another man.
Other evidence used to convict the brothers, originally from Essex, included numerous automatic number plate recognition "hits" showing vehicles they had used travelling between Coventry and Leicester.
A bottle of Bellini bought in Coventry by Miss Imam on Christmas Eve was also found in the fridge at the home of David Cooper, whose allotment shed featured a sign reading: "Don't wind me up... I'm running out of places to hide the bodies."
Officers believe the plot on December 11 may have been aborted because Miss Imam arrived at a hotel in Solihull in a taxi and was dropped off within yards of the main entrance.
Evidence of a further suspected attempt to target the regional marketing manager on December 21 was also presented to the jury.
Detective Chief Inspector Caroline Marsh said: "I would say this is the most callous offence I have ever investigated.
"Most murders that occur are spontaneous events driven by anger or jealousy, whereas in this case what we uncovered was weeks and weeks of planning to kill Sameena, numerous attempts on her life and a really unusual cause of death.
"We very rarely see chloroform homicides.
"It's been a particularly challenging case and a particularly complex investigation and we are extremely grateful to the jury, who have listened to the case and given us the verdict we've had today."
The brothers will be sentenced on Wednesday afternoon.
After the verdicts, Miss Imam's younger brother, Imran Imam, read his victim impact statement to the court.
As his sister's killers continued to show no sign of emotion in the dock, Mr Imam said he was constantly reminded of her loss, even by everyday items such as signposts for places linked to her death.
Mr Imam said: "The circumstances in which Sameena was murdered plague me greatly.
"I think of her last moments, her final thoughts and fears. I constantly imagine the look in her eyes."
Adding that he was haunted by an image of his sister in her makeshift grave, Mr Imam told Judge Patrick Thomas QC: "I worry about the world we live in and the risk that something similar could happen, God forbid.
"I have questions for those who did this. I fear these questions, these open wounds, will never be answered, will never heal."
Statements written by Miss Imam's sisters, Noreen and Nosheen, were read into the court record by prosecutor Timothy Spencer QC.
Noreen paid tribute to her late sibling's beauty, intelligence, kindness and outgoing personality.
Mr Spencer told the court: "She has not come to terms with the fact that her younger sister was murdered by someone she trusted.
"She indicates that she is constantly thinking about how she died and feels she will never know the truth of what really happened to her."
During the trial, jurors were shown computer printouts of David Cooper's eBay purchase history for December 8, showing he ordered 200ml of chloroform for £12.
Some of the metallic elements found in Miss Imam's blood were also purchased by David Cooper over the internet in early December.
Detective Superintendent Mark Payne, head of homicide for West Midlands Police, said: "While we have seen justice done through the courts today, it will never change the fact that Sameena has lost her life in heart-breaking circumstances.
"My sympathy rests with the family and friends she left behind."