The Bavarian Criminal Police Office has now launched an internal investigation to determine if police were justified in shooting a jihadist.

"Künast should not be watching so many bad movies. Who would believe that if someone attacks the police with an axe and a knife, the police are supposed to shoot the axe out of the attacker's hands? That is really clueless and stupid. If police officers are attacked in this manner, they will not engage in Kung Fu. Unfortunately, it sometimes ends in the death of the perpetrator. This will not change." – Rainer Wendt, Chairman of the German Police Union.

"I am a soldier of the Caliphate and am launching a martyrdom operation in Germany. ... I have lived among you, lived in your homes. I planned this in your own land. And I will slaughter you in your own homes and in the streets. ... I will slaughter you with this knife and sever your necks with an axe, if Allah permits. " – Germany's axe-attacker, in an Islamic State video.

A 17-year-old Afghan asylum seeker brandishing an axe and shouting "Allahu Akbar" ("Allah is the greatest") seriously injured five people on a train in Würzburg, Bavaria. The assailant was shot dead by police after he charged at them with the axe.

The teenager, who had claimed asylum after arriving in Germany in June 2015 as an unaccompanied minor, had been placed with a foster family just two weeks before the attack as a reward for being "well integrated."

Bavarian Interior Minister Joachim Herrmann said police had found a hand-painted Islamic State flag in his room at his foster home in the nearby town of Ochsenfurt. They also found a farewell letter to his father which read: "Now pray for me so that I can take revenge on these infidels. Pray for me that I can get to paradise."

Shortly after the attack, the Islamic State released a video purporting to show an Afghan asylum seeker holding a knife and making threats against Germany:

"In the name of Allah, I am a soldier of the Caliphate and am launching a martyrdom operation in Germany. "Here I am. I have lived among you, lived in your homes. I planned this in your own land. And I will slaughter you in your own homes and in the streets. "I will make you forget about the spectacular attacks in France, if Allah permits. "I will fight to the death, if Allah permits. I will slaughter you with this knife and sever your necks with an axe, if Allah permits."

In the video, the Islamic State identified the attacker as Muhammad Riyad, who can be heard speaking Pashto, a language spoken in Afghanistan, Pakistan and Iran. But German media identified the attacker as Riaz Khan Ahmadzai. The discrepancy raised questions about the teenager's true identity.

Police found a Pakistani document in the teenager's room, leading some to believe he may have lied about being from Afghanistan in order to improve his chances of securing asylum. German authorities generally classify migrants from Pakistan as economic migrants and those from Afghanistan as refugees. But Interior Minister Thomas de Maizière said there is no reason to doubt that the attacker was indeed from Afghanistan.

There are also unresolved questions about the teenager's ties to the Islamic State. Herrmann, the Bavarian interior minister, said the video is authentic: "The man in the video is the Würzburg attacker." The federal prosecutor's office in Karlsruhe said it believed "the attacker committed the offense as a member of the Islamic State."

By contrast, De Maizière said the attacker was a self-radicalized "lone wolf" who had been incited by Islamic State propaganda. The public prosecutor in Bamberg, Erik Ohlenschlager, said "We have no evidence that he was in direct contact with the Islamic State."

After the blood-filled train — an eyewitness said it "looked like a slaughterhouse" — came to a stop at a station in Heidingsfeld near Würzburg, the teenager jumped off and tried to escape. Surrounded by police, he lunged at them with an axe. Police shot the attacker dead because "there was no other option."

Green Party MP Renate Künast criticized the police for using lethal force. In a tweet, she wrote: "Why could the attacker not have been incapacitated without killing him???? Questions!"

Künast's comments provoked a furious backlash, with many accusing her of showing more sympathy for the perpetrator than for the victims. The outpouring of anger against Künast indicates that Germans have had enough of their politically correct politicians.

The chairman of the German police union, Rainer Wendt, said:

"The final rescue shot is clearly regulated by law. The policemen were attacked and used their firearm to defend against an immediate danger to life and limb. That is their statutory duty. The Green MP Renate Künast has absolutely no idea about reality of dangerous police actions."

Speaking on N24 television, Wendt added:

"Künast should not be watching so many bad movies. Who would believe that if someone attacks the police with an axe and a knife, the police are supposed to shoot the axe out of the attacker's hands? That is really clueless and stupid. "If police officers are attacked in this manner, they will not engage in Kung Fu. Unfortunately, it sometimes ends in the death of the perpetrator. This will not change."

The head of the police union in Bavaria, Peter Schall, said: "If a police officer is not allowed to shoot in such situations, he might as well stop carrying a weapon."

Mike Mohring, a politician with the ruling Christian Democratic Union (CDU), called for stiffer penalties for those who attack police officers. He said attacks against police are on the rise across Germany and "the only effective deterrent is that the law provides an appropriate penalty." He also said German police should be outfitted with body cameras to protect both the police and the public.

Bavarian Justice Minister Winfried Bausback called on Künast to resign: "Anyone who publicly suspects police in such a situation without any knowledge of the matter — as Künast has done in her tweet — is unacceptable as chairman of the parliamentary legal committee."

Green leader Cem Özdemir distanced himself from Künast:

"I did not understand what she wrote there. It is always a good idea to think about what you are writing before you send a tweet. What are police officers supposed to do if they are attacked? They protected others and they protected themselves. Her view is not the position of my party."

Andreas Scheuer, the general secretary of the Christian Social Union, the Bavarian sister party to Chancellor Angela Merkel's CDU, said Künast's comments were "perverse." He added: "The CSU's policy is: protection of victims takes priority over protection of perpetrators."

German commentator Klaus Kelle wrote:

"Our police in Germany do an excellent job and are hardly ever thanked for it. They are poorly paid ... and repeatedly are whipping boys for errors of policy. Endless overtime, violent attacks, even in harmless situations such as illegal parking, is part of everyday life for our sons and daughters, who serve all of us. "Where are the politicians who support our policemen, rather than those who mindlessly criticize them, as now? Ms. Künast, does the presumption of innocence apply to police officers in this country?"

The Bavarian Criminal Police Office has now launched an internal investigation to determine if police were justified in shooting a jihadist.