The co-pilot, Andreas Lubitz, had been treated by psychotherapists “over a long period of time,” the prosecutor’s office said, without providing precise dates. In follow-up visits to doctors since that time, the prosecutor said, “no signs of suicidal tendencies or aggression toward others were documented.”
Mr. Lubitz’s medical records show no physical illnesses, the prosecutor said, an apparent reference to vision problems that he had been experiencing, although they may have been psychosomatic in nature.
Mr. Lubitz, 27, was at the controls of a Germanwings Airbus A320 jetliner on Tuesday, en route from Barcelona, Spain, to Düsseldorf, Germany, when he apparently set it on a course to crash into the mountains in southeastern France, a French prosecutor has said. Voice recordings from the flight document show that Mr. Lubitz was alone in the cockpit and refused to allow the captain to re-enter as the plane crashed, killing all 150 people on board.
Prosecutors have questioned many of Mr. Lubitz’s friends and colleagues, but have thus far found no indication of a suicide note or a clear motive behind the crash. “In particular there continues to be no verifiable warning of such an act nor has any claim of responsibility been found,” the Düsseldorf prosecutor’s office said in a statement.
Investigators had found no one close to him, whether personally or professionally, who was able to name “any special situation that could serve as a viable indication of a possible motive,” the statement said.
Investigators from Germany, France and beyond are facing the difficult task of determining what motivated Mr. Lubitz, whether it was recent trouble with his eyesight that may have threatened his career as a pilot or issues in his personal life that could have weighed on him. The latest announcement by prosecutors suggests they believe his mental-health problems could well have played a significant role in the crash.
Law-enforcement officials here have mobilized in force to deal with the complex case presented by the crash of Germanwings Flight 9525. More than 200 officers from the Düsseldorf police have worked on what they are calling Special Commission Alps. Roughly 100 officers remain involved in the effort to identify the victims and get to the bottom of how and why they were killed. Two French airplane crash experts are cooperating with the Düsseldorf commission.
“Since the clues accumulated that the crash could have been premeditated, we have formed a murder commission with 50 specialized investigators,” the Düsseldorf police said in a statement.
The evidence gathered in Thursday’s searches at Mr. Lubitz’s apartment and his parents’ house in Montabaur, Germany, was still being analyzed.
Officers are visiting the homes of victims to take DNA samples and fingerprints to aid in the identification of the victims. The physical evidence is being evaluated by Germany’s Federal Criminal Police, and the process could take weeks to complete.
According to a federal law enforcement official in the United States, the Federal Bureau of Investigations conducted interviews in Arizona at the flight school that Mr. Lubitz attended during is training, but they did not find anything “remarkable.” They did several interviews and sent the information on to the Germans.