The man was shot Thursday as he attempted to enter a police station in the northern Paris neighborhood of Barbes, bearing a butcher knife, yelling "Allahu akbar" and carrying a fake explosive device, authorities said.
An image of the ISIS
flag, printed on paper, was found on the man's body, along with a handwritten note in Arabic from him claiming responsibility for the attack and pledging allegiance to ISIS leader Abu Bakr al-Baghdadi, the Paris prosecutor's office said in a statement.
But the note and other evidence are pointing to conflicting information about the man's identity, Paris prosecutor Francois Molins told radio station France Inter on Friday.
His fingerprints match those of a man who had an unspecified encounter with police in southern France last year, Molins said. In that encounter, he provided a certain name and claimed to be Moroccan.
Yet the note found on the man claims he is a Tunisian national, Molins said. And he had a phone with a German SIM card.
"We still need to determine his identification. ... Our investigators are working on all these elements," Molins told France Inter.
Investigators also don't know whether any group directed him to what he did Thursday.
The attempted attack took place at 11:30 a.m., the Paris prosecutor's office said -- a year to the minute since the Charlie Hebdo killings, the first of a spate of deadly jihadist attacks that have roiled the French capital over the past 12 months.
In those attacks, two gunmen killed 12 people
at the offices of the French satirical magazine
, which had angered Islamists for its irreverent approach to Islam
and publication of cartoons of the Prophet Mohammed.
Two more attacks -- one against a police officer and another that included a hostage-taking at a kosher supermarket -- brought the final death toll to 17.
On high alert against the jihadist threat since then, France suffered an even greater blow on November 13, when 130 people were killed in Paris in coordinated attacks
on a concert hall, bars, restaurants and a sports stadium. ISIS claimed responsibility.
Afterward, French President Francois Hollande declared that the country was at war with the terror group and set about strengthening international efforts to strike ISIS on territory it controls in Syria and Iraq.
Speculation over motive
After Thursday's shooting, there was heavy security near the police station in Goutte D'Or in the 18th arrondissement.
Parisians, already wary on a highly sensitive anniversary, were left to speculate about the attacker's motivations: whether he was a lone wolf, a disturbed person or possibly the first wave of the kind of coordinated attacks that struck in November.
Terrorism expert Jean-Charles Brisard, president of the Center for Analysis of Terrorism, noted the attack occurred in the 18th arrondissement, which could have a symbolic connection to the ISIS-claimed November attacks.
The terror group's claim of responsibility for those killings referred to an operation in the 18th arrondissement, but none occurred there. That statement, along with a reference to eight attackers when there had been only seven, led to speculation that an eighth jihadist had planned an attack in the district but backed out.
Regis Le Sommier, co-editor of Paris Match magazine, said he was inclined to think the latest attack was self-directed, rather than coordinated by the central command of ISIS or another terror group, since it took place on the anniversary of the Charlie Hebdo assault.
, he said, jihadists had not shown any particular interest in striking on the anniversaries of terror attacks despite the sensitivities around the dates. "That probably makes me think that he decided to do it on his own," he told CNN.