Berlin, Germany(CNN) A man arrested over the killing of a senior German politician earlier this month is believed to have links to the far right, prosecutors said Monday.

Walter Lübcke, who was president of the Kassel regional council in central Germany, was shot in the head at close range on the terrace of his home in the small village of Istha, in the early hours of June 2.

Sixty-five-year-old Lübcke was a member of Chancellor Angela Merkel's ruling Christian Democrats and an outspoken supporter of the government's pro-migrant policies in the wake of the 2015 refugee crisis.

The 45-year-old suspect was arrested on Saturday in Kassel based on traces of DNA evidence from the crime scene, according to the Hesse state office of criminal investigation and Kassel's public prosecutor. The suspect has a long criminal record, police said.

The past life and the "openly expressed opinions and public views" of the suspect linked him with the far right, Michael Schmidt, a spokesman for the federal prosecutor's office, told a news conference Monday.

"Based on the current state of investigations, we assume that there is a right-wing extremist background to this act," Schmidt said, before adding there was no evidence that the suspect was involved in a right-wing terrorist group.

Investigations are ongoing and officials confiscated computer equipment from the suspect, said Schmidt.

Pro-migrant policies attract death threats and attacks

According to police, Lübcke previously received death threats after a YouTube video emerged of him defending the country's immigration policies at a public meeting in Kassel in October 2015. The meeting was also attended by members of Pegida, a far-right anti-Islam movement.

In the video, Lübcke says: ''You have to stand up for your values. If you don't share those values, then anyone is free to leave this country if they don't agree." Some members of the crowd could be heard shouting "get out, get out" in response.

German President Frank-Walter Steinmeier condemned hate posts toward the pro-migrant politician. ''The way some individuals on social media are attacking his death, taking satisfaction from it and applauding it is cynical, tasteless, revolting and offensive in every way," he said in comments at a German town association event.

Interior minister Horst Seehofer also told the daily newspaper Tagesspiegel that "if someone is so hated, just because he had liberal views, that is the decline of human morality."

The killing of Lübcke is not the first attack on a pro-migrant German politician in recent years.

In 2016 a man -- referred to as Frank S. -- who also reportedly opposed Germany's open-door refugee policies was sentenced to 14 years in prison for stabbing Cologne mayoral candidate Henriette Reker, according to the New York Times.

Another German politician well-known for his pro-refugee policies, Altena town mayor Andreas Hollstein, was stabbed in the neck at a kebab shop in 2017 by an assailant who reportedly said: "You are leaving me die of thirst while you bring 200 refugees to Altena."

Merkel opened Germany's doors to more than a million migrants in 2015. But her policy, hailed by humanitarians, also attracted fierce criticism from the right, particularly following a number of terrorist attacks across the country in summer 2016.

Riding the wave of public discontent was the anti-immigration, anti-Islam AfD. In the 2017 federal election, it became the third largest party in the Bundestag and the first far-right party to enter the country's parliament in almost 60 years.

Now, the tide appears to be shifting again, with the environmentally focused and left-wing Greens surging to second place in May's European parliamentary elections, pushing the AfD into fourth.