"It was an awful atrocity, an unbelievable beating. They were totally cold-blooded," prosecutor Daniel Larson told the TT news agency.
Both men have denied the charges of murder and aggravated robbery.
The safe that was stolen from the farm, which is believed to be to reason behind the attacks, is still missing.
Despite the denials, prosecutor Daniel Larson believes there is sufficient evidence to formally charge the men.
“The evidence includes, among other things, the positioning of mobile phones, shoe prints found at the crime scene, and that the same unusual cables used to bind the victims were found with one of the men at his arrest in Poland,” Larson said in a statement.
The indictment stemming from the massive preliminary investigation totals around 2,500 pages.
In his summary of the case presented alongside the filing, Larson detailed the brutal violence used against the elderly couple when they were killed on October 19th in the small village of Långered, outside Alingsås.
The elderly couple, 69-year-old dairy farmer Torgny Antby and his 71-year-old wife Inger, were found dead after failing to turn up for their afternoon performance with the local choir.
According to Larson, the suspects attacked the elderly couple as they went out to feed their cows around 5.30am.
"The suspects clearly knew the procedures on the farm, so we think they had planned this for some time," he said.
Torgny was knocked to the ground near the cows before receiving a fatal blow to the head with an iron pipe, according to Larson.
The killers then removed the man's boots and tied his hands and feet together before trying to hide the body.
While prosecutors believe a safe at the house was the robber's goal, they remain curious as to how the suspects failed to find the key to the safe, which was hanging among other keys at the house, as well as the 9,000 kronor in cash in Torgny's jacket pocket.
"They could have gotten at the safe in a thousand different ways without touching a hair on [the victims]," said Larson.
According to Larson, Inger was strangled to death with a force so powerful that it broke her hyoid bone at the base of her throat and damaged her windpipe.
Both victims were found with their wrists and ankles bound by cables.
Larson also filed an alternative charge of accessory to murder, theorizing that the men may not have carried out the actual killings, but were instead involved in their preparation and helping the killers make their getaway.
Other evidence tying the men to the crime scene, according to the indictment, is used toilet paper which contained human excrement from which police were able to take DNA samples.
The trial of the two men is expected to start on June 4th and last six days.