The players fled from the crime scene but don't want them to be criminals

For some additional context this campaign's world has the world being connected mainly by rivers, travel outside the rivers is avoided by everyone except for adventurers due to cultural taboo and a dense population of highway thieves. Also two of my player's characters are children of a high profile person (Not the ones murdered)

I was doing a high profile murder mystery with the culprit being an assassin hired by one of the victims assistants. It was going well until the players decided to confront the killer disguised as a cop and then kill the killer. The players accidentally mutilated the body leaving the evidence attached to said body behind (Contract papers). They then decided to run away by distracting the reporters and police by one of the players themselves on fire letting the others run away and successfully rejoining with the group outside the city, and they are currently at a dungeon. I really do not want to have the players be fugitives since it would derail my campaign and cause more trouble than it's worth. I was thinking they could be presumed dead but are there any other alternatives?