MUNICH — When German Interior Minister Thomas de Maizière was talking last week about the arrests of the three alleged members of the terror group ISIS, he noted that there might also be individual perpetrators being "remote controlled." He appears to be talking about the culprits in the Würzburg and Ansbach attacks this summer in the German state of Bavaria.

"Remote controlled" — that's a whole new category from the terrorism investigators' point of view. The agents who are dealing with this new phenomenon act with the presumption that suspected ISIS instructors move freely across the Internet, recruiting new candidates who are likely to connect with them digitally — "followers-as-terrorists," in a way.

Würzburg, July 18, axe attack on a train. Riaz Khan A., the 17-year-old culprit had arrived in Germany as a refugee from Afghanistan without his parents in 2005. Nobody had noticed him as a "extremist." But in secret, the boy was chatting online with alleged ISIS instructors.

Chat-partner: "What weapons do you need for the killing?"

Riaz A.: "Knives and an axe are placed ready."

Chat-partner: "Brother, don't you think doing it with a car would be better?"

RiazA.: "I don't know how to drive a car."

Chat-partner: "You should learn it."

RiazA.: "Learning takes time."

Chat-partner: "The damage would be considerably bigger."

RiazA.: "I want to go to paradise tonight."

The night of July 18, Riaz A. and the presumed ISIS guide were in particularly close contact, beginning at 6.34 p.m..

Riaz A.: "Brother, I'm sending you my video. I will carry out an attack with an axe in Germany today."

Riaz A. sent a video to an ISIS propaganda-agency: "I'm a holy warrior of the Islamic state. I will kill you with my knife and chop your heads with my axe, God willing."

Chat-partner: "Not with a knife. Do it with the axe. If you carry out the attack, God willing, the Islamic State will take responsibility for you."

RiazA.: "I'm sending you the video now."

Chat-partner: "Secure it quickly."

RiazA.: "Pray for me to become a martyr. I'm waiting for the train."

Shortly after that Riaz A. got on the regional train armed with a knife and an axe. After a while he wrote once more.

RiazA.: "I'm about to start."

Chat-partner: "Paradise is awaiting you."

Riaz A. severely injured four passengers on the train. On the run he attacked police officers and was eventually shot by a special task force agent.

Ansbach, July 24 suicide bombing outside a wine bar : The Syrian refugee Mohammed D. arrived in Germany in 2014. His family is believed to have been killed in Syria. Before that the 27-year-old had applied for asylum in Bulgaria, claiming he had been heavily abused there. In Ansbach a group of refugee workers took care of him. His application for asylum had been turned down. He attempted to kill himself, twice.

Mohammed D. too was in contact with presumed ISIS instructors. He too had been asked to kill. The assault was supposed to take place at the music-festival "Ansbach Open 2016". Beforehand, Mohammed D. had sent the instructor a photo of the place where the festival was about to take place.

Mohammed D.: "This place will be crowded."

Chat-partner: "Kill them all, so they'll all be lying down on the ground."

July 24, the day of the attack, the 27 year old once again contacts his instructor.

M.D.: "The party's over soon, and there's a doorman."

Chat partner: "Go into the middle of the crowd, run, and do it."

M.D.: "Pray for me. You have no idea what's happening to me right now."

Chat-partner: "Forget the party, go to the restaurant. What's wrong with you? I'd do it for two people. Trust in God and go to the restaurant."

M.D. headed for the wine bar close to the festival area. That's where his bomb went off. Fifteen people were hurt. Mohammed D. died. The bomb had most likely detonated by accident. ISIS claimed D. had been an experienced warrior, a "soldier."

Meanwhile, a lawsuit in Lower Saxony in October against a 16-year-old student with German-Moroccan origins, named as Safia S., will start at the Higher Regional Court. On February 26, she allegedly stabbed a policeman at the Central station in Hannover. According to the investigations of the Federal prosecutor, the student had asked an ISIS instructor for help via a messenger for planning the act. Her guide presented herself to Safia as "Leyla".

One day before the act, "Leyla" gave her final instructions. Under a pretext the student should attract the policeman into a corner of the station, stab him, steal his gun, and then shoot. Safia S. explained she didn't know how to handle a gun. "Leyla" promised to help her. All she needed was a picture of the guns German policemen used.

The student didn't send the photo, but she sent a confessor video to ISIS. The next day, she took two knives, went to the train station and stabbed a policeman in the neck, leaving him seriously injured

Investigators to this day still have no idea who "Leyla" is.