Two French officials have said that the Champs-Elysees gunman was detained in February for threatening police.
The officials - who spoke on the condition of anonymity - said the gunman was detained at the end of the month after speaking threateningly about the police, but later released due to a lack of evidence.
They also reported he was convicted of attempted homicide in 2003 in shootings on two police officers.
A man believed to be the principal attacker was shot dead at the scene, after a police officer was killed and two others seriously wounded.
A second man wanted in connection to the attack is reported to have handed himself into police.
The attack comes just days before France's presidential elections.
Prosecutors describe French national with a long history of violence and criminal offences but few obvious signs of radicalisation.
A police officer has been killed and two others wounded in a shooting in the centre of Paris - here's what we know so far.