Doctors let him go. The next day, he stabbed three people.

A man attacked strangers at a Swiss train station just hours after a mental clinic freed him.

A quiet morning became a nightmare when a man with a knife chased school kids and stabbed three people. When the systems built to keep us safe fail, normal people pay the price.

On Thursday morning, a knife attack shook the train station in Winterthur, Switzerland. Police arrested Nesip Dedler, a 31-year-old dual citizen of Switzerland and Turkey. He is accused of wounding three people.

Witnesses saw the attacker run past a group of young school children. Their teacher ran in front to shield them. People nearby heard the man shout "Allahu Akbar" as he ran.

Just four days earlier, Dedler called police and spoke in a confused way. Officers took him to a mental clinic. Doctors let him go on Wednesday, saying he was not a danger.

The very next day, he carried out the attack.

What the evidence shows

3 Swiss citizens wounded, aged 28, 43, and 52.

• 1 person in serious condition, 2 with minor wounds.
• 24 hours between his release from the clinic and the knife attack.
• 15 police cars sent to the train station.
• 1 closed mosque where police had looked into him before.

THE BIGGER QUESTION

How does someone go from a mental health ward to a busy train station with a knife in one day? This story shows a deep gap between health care and public safety. We must ask if doctors are trained to spot the signs of a person with radical views.

Dedler was already known to police for violent events at a local mosque. Why did this warning sign not stop his release?

WHAT HAPPENS NOW

The town of Winterthur is now in shock. People will want to know how the state will change the rules on how it tracks people who show both mental illness and radical views.

WHAT WE STILL DON'T KNOW

1. Why did the clinic doctors decide he was safe to go free?
2. Did police share his past violent record with the doctors?
3. How did the suspect get the knife?