Samuel Woodward (pictured), 20, of California, has been charged with the murder of Blaze Bernstein, 19

The man accused of murdering University of Pennsylvania sophomore Blaze Bernstein, 19, in California an active member of a neo-Nazi group, ProPublica reported.

Samuel Woodward, 20, has been charged with the murder of Bernstein, who was stabbed to death earlier this month while visiting his parents in Southern California over winter break.

Social media posts made by Woodward depicting neo-Nazi ideas surfaced after Bernstein's death.

But ProPublica has now received confirmation from three people close to Woodward that he was active in a neo-Nazi organization called Atomwaffen Division. The name translates to 'Nuclear Weapons Division'.

Bernstein, who prosecutors say was stabbed more than 20 times by Woodward and then buried in a shallow grave, was Jewish and openly gay.

Woodward told police that Bernstein tried to kiss him in Borrego park, where Bernstein was later found dead, the night of the murder. The two went to high school together.

Woodward is reportedly a member of a neo-Nazi organization called Atomwaffen Division. Pictured is an image found on the group's website

Prosecutors are investigating whether Bernstein's murder was a hate crime. Bernstein (pictured) was openly gay and Jewish, and his mother told the Los Angeles Times that she always feared for her late son's safety

The victim's mother, Jeanne Pepper Bernstein, told the Los Angeles Times last week that she was 'concerned for [her son's] safety always'.

She said: 'I'm concerned about the fact that he is Jewish. I'm concerned with the fact that he is gay or the fact that he is small.'

Prosecutors are looking into the possibility that the murder was a hate crime.

Two of the sources who revealed Woodward's background to ProPublic were his friends and one used to be a member of Atomwaffen Division.

The neo-Nazi group that Woodward was allegedly a member of has filmed itself burning the American flag and the constitution.

The above advertisement for a sniper was found on Atomwaffen Division's website

Woodward (pictured) has not yet entered a plea. He is set to appear in court February 2

Borrego Park in Foothill Ranch, California (pictured), is where prosecutors say Woodward stabbed Blaze more than 20 times before burying him. Bernstein's body surfaced in the park on January 10 after rain unearthed it

Blaze's parents, pictured during the search for him before his body was discovered, said they were devastated by the news of his death

The group's website describes the Atomwaffen Division as 'a Revolutionary National Socialist organization centered around political activism and the practice of an autonomous Fascist lifestyle'.

The website's 'Who we are' section reads: 'As an ideological band of comrades, we perform both activism and militant training (hand to hand, arms training, and etc.).

'We spread awareness in the real world through unconventional means (and it has worked).

'We often go hunting, adventuring, and a group favorite is urban exploring. We have various specialists in the group ranging from many occupations... Joining us means serious dedication not only to the Atomwaffen Division and its members, but to the goal of ultimate uncompromising victory.

'As it must be emphasized: no keyboard warriorism... if you don't want to meet up and get things done: don't bother.'

One source described Woodward as 'as anti-Semitic as you can get'. Woodward reportedly joined Atomwaffen Division in 2016, attended group meetings in Texas and there completed a three-day training camp.

The training camp armed members of the group with hand-to-hand combat, camping, survival and firearm use skills, the former Atomwaffen Division member told ProPublica.

The website said it had also obtained pictures of Woodward at one of the group's meetings. In one, Woodward can reportedly be seen doing a Nazi salute.

Woodward is trained to use assault rifles and handguns and has organized Atomwaffen Division members in California, it is claimed.

The Atomwaffen Division has also been connected to murders in Florida and Virginia. It was founded in 2015 and consists of about 80 members.

The former member who spoke with ProPublica said the group has grown since the explosive 'Unite the Right' protest - which left one protester dead - in Virginia last summer.

Joanna Mendelson, a researcher at the Anti-Defamation League's Center on Extremism told ProPublica: 'Their rhetoric is some of the most extreme we have seen.'

Woodward is set to appear in court on February 2. He has not entered a plea.