April 21 (UPI) -- The man who shot a police officer dead and injured two others in Paris was not previously named in any French security watch list as a potential risk, officials said Friday.
Police identified the accused gunman, who was shot dead on Paris' famed Avenue des Champs-Élysées Thursday, as Karim Cheurfi -- a 39-year-old French citizen who lived on the outskirts of the city.
Though he had a long criminal history, police said, he was never deemed risky enough to be placed on France's official Fiche S watch, which alerts authorities to potential militants. He had, however, served more than a decade in prison for unsuccessfully trying to kill another police officer in the mid-2000s.
Authorities said Cheurfi was released from prison in 2015 -- and re-arrested again in February for threatening to kill police. However, he was released from custody due to lack of proper evidence.
Paris Prosecutor François Molins on Friday said Cheurfi had shown no signs of "radicalization."
"Investigations will now focus on determining [whether he had] the benefit of possible accomplices," he said at a news conference.
According to investigators, Cheurfi -- armed with an automatic AK-47-type weapon -- started shooting at a group of officers in a police van Thursday night. One was killed and two were wounded before the gunman was shot dead by return fire as he attempted to flee on foot.
A handwritten note found near the gunman's body indicated allegiance to the Islamic State. The busy street was evacuated, with at least one restaurant shielding customers in its basement.
"On the face of it, the officers were deliberately targeted," Interior Ministry spokesman Pierre-Henry Brandet said.
The terror group took credit for the attack, though that claim is viewed skeptically by some authorities. French President Francois Hollande classified the incident as a terrorist attack.
After the shooting, French presidential candidates announced they would temporarily suspend their campaigns. With the first round of voting scheduled for Sunday, center-right candidate Francois Fillon, far-right candidate Marine Le Pen and leftist candidate Emmanuel Macron announced they halted their campaigns in light of the attack.
In opinion polls, the three lead the list of presidential candidates in popularity. They were participating in a televised political debate on Thursday night when the shooting started.
More than 50,000 police officers were on hand for security in Paris this week, as the vote nears. Hollande, who's not seeking re-election, convened a meeting of the national defense council on Friday.
At the debate, the three leading candidates expressed support of the police, with Fillon saying there is "no room for pursuing an election campaign today or tomorrow because, first of all, we have to demonstrate our solidarity with police."
Far-left candidate Jean-Luc Melanchon said that panic should not "interrupt democracy," and later, Le Pen called on Hollande to restore border controls and immediately expel or detain anyone in France suspected of radical Islamist sentiments.
U.S. President Donald Trump tweeted Friday that he believes the shooting will sway France's presidential vote in conservatives' favor.
"Another terrorist attack in Paris. The people of France will not take much more of this," he wrote. "Will have a big effect on presidential election!"