He wanted to tip the two officers, one of whom was female, about a teenage gang that was driving around and disturbing the neighbourhood.
"I leaned down and placed my arm on the car's door and they told me to remove my arm. I told them I wasn't going to because the car was as much mine as it was theirs; I pay taxes," said Djerfsten.
According to Djerfsten, that was when he was attacked.
"They came from both sides with batons and started hitting me. I tried to protect myself the best I could with my arms - and it's possible I may have hit one of them," said Djerfsten.
The whole incident was caught on tape by the petrol station's security camera. The video has now been released to the media as part of the prosecutor's case against the two officers.
Two days after the alleged attack, a bruised Djerfsten went to the police station to report the incident - only to find out that the two officers had already pressed charges against him. Djerfsten was being charged with assault.
The police deny the charges and state that it was Djerfsten who assaulted them first. They say his punches were not caught on tape because there is an 0.8 second gap between images on the security system's tape.
"A punch is very fast," said the policewoman charged.
Svenska Dagbladet reported that the chief prosecutor, Christer Ekelund, will use the tape as evidence during the trial. The two police are being charged with assault, misconduct and false testimony. The prosecutor believes the evidence against them is strong and confirms Djerfsten's version of events.
"The tape shows what really happened," said Ekelund
Speaking in Saturday's Dagens Nyheter, Djerfsten said that the incident is highly damaging to the reputation of Sweden's police.
"It's not like when I was a boy and police constables patrolled the streets in pairs. Then you could ask them anything and get reasonable answers," he said.
"But these two shouldn't be police officers. They're not capable of doing the job. Police should be sociable and listen to people."