The Islamic State militant group has claimed responsibility for the attack, which killed three people at a festival marking the city of Solingen’s 650th anniversary.
Police have arrested the person suspected of carrying out a knife attack that left three people dead at a festival in Germany, an official has said.
The 26-year-old man handed himself in and his involvement is currently being “intensively investigated”.
A 56-year-old woman and two men, aged 56 and 67, died following the attack in the city of Solingen on Friday. Eight people were injured, four seriously, while “many other people have suffered mental stress”.
Police said the attacker appeared to have deliberately aimed for his victims’ throats.
As part of investigations, a municipal accommodation center has been searched and a person found there who is said to have been in contact with the perpetrator – this person is currently being treated as a witness.
The internal affairs minister of North Rhein Westphalia, Herbert Reul, told the German public television network ARD on Saturday night: “We have been following a hot lead all day.
“The person we have been searching for all day has been detained a short while ago.”
Mr Reul added police not only have “clues” but also have collected “pieces of evidence”.
Earlier on Saturday a 15-year-old boy was previously arrested suspected of failing “to report an imminent crime,” but police and prosecutors said at a news conference in the afternoon that there were no further suspicions.
Police also made another arrest in connection with the attack.
They said the arrest followed an operation to access a building housing asylum seekers in Solingen as part of their investigation.
Islamic State has claimed responsibility for the attack but offered no immediate evidence to support its claim.
A security source told the IS-affiliated media arm Amaq Agency that the suspect “was a soldier from the Islamic State, and he carried it out as revenge against Muslims in Palestine and everywhere”.