The victim, Ari Fuld, 45, was well-known amongst settlers as a pro-Israel advocate. According to his Twitter account, he had planned a lecture tour in the United States in November.
Investigators said the the attack was motivated by a "family conflict", not organised crime.
German police were searching on Sunday for possible contacts of an IS fighter believed to be behind a terror plot against a major shopping mall.
Thousands of people attended a vigil Monday in memory of the five victims mowed down by a car at Melbourne's busiest mall last week as police charged the suspected driver with murder.
Three robed women tricked their way into a Mombasa police station where they stabbed one officer and set fire to the building with a petrol bomb before being shot dead, an officer and a witness said on Sunday.
A German-Iranian teenager who shot dead nine people in Munich was a deranged lone gunman obsessed with mass killings who drew no inspiration from Islamist militancy, police said on Saturday.