Police in the southwestern German state of Baden-Württemberg on Friday said they had arrested an 18-year-old suspect on suspicion of conspiracy to commit a knife attack on synagogue visitors in the city of Heidelberg.

Investigators found a link to the teenager after examining evidence taken earlier from a separate suspect.

What do we know about the case?

The teenager is suspected of plotting an attack with a 24-year-old suspect who police captured earlier this month after a raid on the man's apartment turned violent, police said.

"The intended goal was discussed as the killing of one or more visitors during the attack on the synagogue," said police, adding that the pair had planned a "martyrs' death," in which they would be fatally shot by officers. 

Police raided the home of the older man — suspected of preparing a serious act of violence endangering the state — on May 3 in the town of Bad Friedrichshall.

While officers were in his flat, the man suddenly fled through a window, taking several kitchen knives.

Police chased and caught up with him but, instead of putting the knives down, he threw a knife at one of them and ran toward an officer. Police shot the suspect and arrested him.

IT device trail to teenager

Forensic IT intensive investigations revealed the link to the 18-year-old living in Weinheim, near Heidelberg.  

Because of suspicion of conspiracy to commit murder arising from the chat history, the local Karlsruhe public prosecutor's office obtained several orders against the suspect. 

A standby judge issued a search warrant, which police and special forces executed early last Saturday. The man was arrested unharmed at his home address.

During the search of the younger suspect's apartment, several IT devices and other electronic evidence were seized.

Authorities have said there are no indications of an imminent threat to visitors to the synagogue.

rc/wd (AFP, dpa)