Leaked new autopsy evidence in the case of two American teens accused of killing an Italian undercover police officer Mario Cerciello Rega in Rome in July paint a disturbing picture of extreme potentially drug-fueled violence.

The report obtained by The Daily Beast comes as Finnegan Elder, 19, and Gabriel Natale, 18, both of San Francisco, sit in Rome jail cells while investigators continue to unravel the events that led to Rega’s violent death.

Elder allegedly confessed to stabbing Rega with a 7-inch military grade knife he had carried with him from the United States, according to police. Elder’s lawyers say he acted in self defense and that the police did not properly identify themselves.

Details from the police officer’s autopsy obtained by The Daily Beast show that some of the 11 stab wounds that led to Rega’s death were so deep the handle of Elder’s knife left bruises on the officer’s skin.

None of the stab wounds occurred on the front of the officer’s body, according to the report, but both of Rega’s lungs were punctured in addition to other vital organs. The autopsy says the stabbing was carried out with “extreme violence.”

Before the murder police claim the Americans allegedly approached an interloper in an attempt to buy drugs in central Rome on the evening of July 26. But when they discovered that what they purchased from a drug dealer turned out to be crushed aspirin, they returned to the interloper to get their money back.

When that was not possible they stole the interloper’s backpack which had a cellphone in it. When the man called his cellphone, the Americans made a plan to meet him to return the bag in exchange for a gram of cocaine and their money back. But Rega and his partner met the Americans instead. It is unclear if the interloper or the drug seller were actually informants or why police were so willing to help retrieve the bag.

New details also show that neither Rega or his partner Andrea Varriale had their weapons, badges or handcuffs when they met the Americans. Varriale is currently under investigation for responding to a call without his service weapon. It’s against the law in Italy for an active police officer not to be armed.

The Daily Beast has also obtained a vital police document that chronicles the cellphone messages by Elder and Natale before and after the murder. The document contains photos from both young men’s phones that show them holding guns, knives and drugs.

Natale has claimed that he knew nothing about Elder’s knife or the stabbing, but the police report shows surveillance photos of the two young men returning to the hotel together after the murder. It also alleges that Natale’s fingerprints were found alongside Elder’s on the ceiling panel where the murder weapon was found inside the hotel room the young men shared.

In the report authorities outline a series of text messages Natale allegedly sent to a friend identified as “Vallby” last spring in which he sends Amazon links of knives he likes. The reports shows he also had photos of himself holding various guns and knives.

In another exchange, Natale’s mother accuses him of selling drugs, which he denies. “I'm not talking about your second time using mushrooms,” Natale’ mother writes to her son. “I'm talking about the fact that it is bullshit that you are not still selling drugs since you do not have a job and you continue to buy stuff. Expensive stuff. You lie to me constantly.”

Records from Elder’s phone show pictures of hundred dollar bills, some rolled next to what appears to be cocaine on a table, and photos of marijuana with the title “Buffalo Breathe” superimposed on them.

In one photo from his cellphone he is holding three blue tablets with the words “Fuck Xanax boy” written in meme form. Elder’s phone also has a number of photos of the murder weapon used to kill Rega. One with the words “I kill you” superimposed on top. Some photos are apparent selfies of Elder with a pistol pointed at his temple.

Elder’s lawyer has withdrawn a petition that his client be released from prison during the investigation. Natale, who has not been implicated directly in the stabbing but was sharing a hotel room with Elder where the weapon was hidden in a ceiling tile, is expected in court Monday to petition a judge that he be released during the investigation.