French prosecutors say a note praising Isis was found near the body of a gunman who shot a policeman dead in Paris.
Xavier Jugelé, 37, was blasted in the head by the gunman at around 9pm on Thursday in the Champs-Elysees.
The murderer, who was killed by police, has since been named as Karim Cheurfi.
Anti-terrorism prosecutor Francois Molins said a piece of paper fell out of the pocket of Cheurfi, a 39-year-old with a criminal record.
Mr Molins said the note praised Isis and listed the addresses of security sites.
The extremist group claimed responsibility for Thursday's attack, which also saw two police officers injured, one seriously.
Mr Molins said Cheurfi had a long police record, including for trying to attack police in the past.
The prosecutor said Cheurfi was arrested in February, but later released for lack of evidence of a threat.