The Tunisian now wanted throughout Europe has six aliases, three nationalities — and links to the same brand of Islamic extremism that has drawn at least 6,000 of his countrymen to jihadi networks.
Anis Amri, who turns 24 on Thursday, is in grim company with other Tunisians claimed by the Islamic State group. One of them includes the man who mowed down 86 Bastille Day revelers in the southern French city of Nice last July and another who gunned down dozens of tourists on a beach in Tunisia.
At least 6,000 Tunisians have left home to join Islamic State extremists, forming the single largest nationality of foreign fighters for the group. Many trained at IS camps in neighboring Libya. Others made their way to Syria and Iraq.
It's still not known whether Amri had direct links to Islamic State, but the extremist group claimed responsibility for the Monday night truck attack on the Berlin Christmas market that left 12 people dead and 48 injured.
Amri's wallet was found inside the cab of the truck, and German authorities on Wednesday issued a warrant for him, listing three different nationalities and six different names and birthdays that he presumably provided.
His birthdate is officially listed in the warrant released by German police as Dec. 22, 1992. In a pair of photos, he has a sparse beard and no mustache.
Tunisian anti-terror police interrogated Amri's relatives Wednesday in the central Tunisian town of Oueslatia, a spokesman, Sofiane Selliti, told The Associated Press. He did not say how many family members were present.
Amri's father told Tunisia's Mosaique FM radio that his son left his homeland about seven years ago, spent four years in a prison in Italy after being accused in a fire at a school there then moved to Germany more than a year ago. The father said he had no contact with his son, although Amri's brothers did.
Mosaique FM cited security officials as saying that Amri had been convicted in absentia for aggravated theft with violence in Tunisia and sentenced to five years in prison. No dates were given.
After his prison time in Italy, Amri was ordered expelled, the Italian news agency ANSA reported. However, Tunisian authorities didn't finish all the paperwork in time, so Amri never was sent back to Tunisia.
The suspect's family lives in poverty and his parents are divorced, according to Mosaique FM radio.
State prosecutors in Berlin launched an investigation of Amri on March 14 following a tip from federal security agencies, who warned that he might be planning a break-in to finance the purchase of automatic weapons for use in a possible future attack.
Surveillance showed that Amri dealt drugs in a notorious Berlin park and was involved in a bar brawl, but no evidence was found to substantiate the original warning.
The surveillance measures were called off in September.
Separately, Amri's asylum application was rejected in July. German authorities prepared to deport him but weren't able to do so because he didn't have valid identity papers.
As for the Berlin attack, it's not the first time a suspect has discarded identifying documents in a vehicle. The attackers who carried out the 2015 massacre at the Charlie Hebdo newspaper in Paris did so, as did one of the Nov. 13 attackers in Paris and the Tunisian truck attacker in Nice, Mohamed Lahouaiej Bouhlel. In all of those cases, the attackers were killed.
"It could be to kind of leave a trace and strengthen potential claims of responsibility," Otso Iho, an analyst with IHS Jane's, said of the abandoned ID documents.
Amarnath Amarasingam, a scholar at George Washington University's program on extremism, says he believes Amri did have ties with the Islamic State group.
"The fact that ISIS took credit for the attack before the attacker was arrested signals to me that he was in direct communication with someone in ISIS," he wrote in an email to the AP. "We can probably expect a video or a statement from the attacker himself fairly soon."