I didn't see this posted anywhere so here I go.
Wow. This case makes the Amanda Knox case look paltry. The evidence here is overwhelming. The teens are on video running with a backpack they stole after a botched drug deal. The owner of the backpack called police. When officers attempted to stop them one of the boys stabbed him to death and they ran. Police went to their hotel room. When they looked in the ceiling they found the knife and the clothes the boys had worn during the attack. They also found that the teens had made arrangements to fly back to the US the next day.
https://abcnews.go.com/International/wireStory/italy-detains-americans-19-slaying-policeman-64602777
The owner of the backpack who set up the drug deal says he was threatened by the boys. He says the teens demanded money and drugs in return for the backpack.
The boy accused of stabbing the officer has a previous assault arrest that resulted in serious injuries. He brought the knife with him from the US. He has admitted to stabbing the officer.
https://www.cnn.com/2019/07/31/europe/finnegan-lee-elder-charges-california-intl/index.html
The fathers are now in Rome and one boy has turned on the other.
I don't think these boys are going to get away with this.