"We now have a clear picture of how it [her death] happened, and that image is reinforced by the autopsy report," Deputy Chief Prosecutor Lars-Göran Wennerholm told the TT newswire on Monday.
"I want to take things in the right order and to talk to relatives and even the suspect first," he added, when questioned by Swedish newspaper Dagens Nyheter (DN).
But he said that evidence against the 35-year-old man arrested on suspicion of murdering the teenager was mounting and revealed that he had asked Skaraborg District Court for permission to hold the suspect for another month, until September 22nd.
The prosecutor confirmed that Sweden's National Forensic Centre (NFC) was still analysing DNA traces found on some of Lisa Holm's clothes and belongings that were found close to the crime scene.
"I have said before that there are several DNA [traces] that connect the suspect to Lisa Holm. Now we have a number of DNA hits, including his blood on Lisa Holm's belongings. DNA in the form of blood... is strong evidence," he told DN.
Lisa Holm was last seen alive at a café in Blomberg near Lidköping in June after working a shift there.
Lidköping is a small town in a rural area north east of Gothenburg, and is close to two of Sweden's largest lakes. It is around 50km from the teenager's home town, Skövde.
Two brothers and a woman were initially arrested
after police found the body of the teenage schoolgirl, a week on from her disappearance. The woman and the younger man were later released, but officers have continued to hold their main suspect.