Two men have been charged with assisting the man believed to be responsible for the attacks on a shul and a café over the weekend in Copenhagen.
The men, who police have not named, will appear before a hearing on Monday, accused of providing Omar El-Hussein with a weapon, which he reportedly used in two separate gun attacks in the Danish capital. They are also suspected of disposing the weapon and helping the gunman hide later.
Jewish volunteer Dan Uzan was killed on Sunday while guarding a synagogue during a batmitzvah at the Central Synagogue in Copenhagen.
The shooting took place in the early hours of Sunday morning and followed an earlier attack at a cafe in the city in which one person was killed and three were injured.
Police later killed El-Hussein, who they believe was responsible for both attacks.
It is thought around 80 people were in the synagogue at the time of the attack - 1.30am on Sunday - celebrating the simchah. Community leaders said they had requested additional police support following the cafe shooting.
Mr Uzan, who was 37, was a volunteer guard, similar to those who assist the Community Security Trust guarding Jewish buildings in Britain.
The Israeli Foreign Ministry said his father was Israeli and his mother Danish.
On Facebook, friends described Mr Uzan as one of the "loveliest, most welcoming people you could meet".
CST in Britain tweeted: "Our thoughts and sympathies are with the Danish Jewish community and the victims of terror in the Copenhagen attack.
"We express solidarity with everyone who helps to protect Jewish communities around the world."
In a statement, the Board of Deputies of British Jews said: "Once again Jews at prayer, this time at a Copenhagen synagogue, have come under attack in Europe.
"The Board condemns these attacks in the strongest possible terms. Our thoughts are with the families of all those who were killed and wounded in these shocking attacks in Denmark. We stand in solidarity with the Jewish community in Denmark and have contacted them to express our sympathy and our support."
The earlier cafe attack appeared to have been carried out by Islamists targeting Lars Wilks, an artist who has received death threats since publishing images of the Prophet Mohammed.
The café had been hosting an event titled "Art, blasphemy and the freedom of expression" when the shots were fired.
