Updated

Blaze Bernstein was stabbed at least 20 times in what authorities are reportedly investigating as a possible “act of rage,” a report on Monday revealed.

The body of 19-year-old Bernstein, a pre-med sophomore at the University of Pennsylvania, was found Jan. 9 buried in a shallow grave at Borrego Park in Lake Forest, California, after his parents reported him missing a week earlier.

Authorities on Friday arrested Samuel Woodward, 20, as a suspect in the Ivy League student’s death, and he’s reportedly expected to be formally charged Tuesday, the Orange County Register reported.

A former high school classmate of Bernstein’s, Woodward was the last person to see him alive. On the night of Jan. 2, the two drove to Borrego Park, and, according to Woodward, Bernstein exited the vehicle and walked alone into the park.

Woodward told investigators he waited for Bernstein for an hour, left to visit his girlfriend — whose name and address he claimed he couldn’t remember — before he circled back hours later to find him.

Bernstein, according to the Orange County Register, had texted friends in June that Woodward was about to “hit on me” and “he made me promise not to tell anyone … but I have texted every one, uh oh.”

More on Blaze Bernstein...

Woodward told investigators that on Jan. 2, Bernstein had kissed him on the lips and that he pushed Bernstein away.

Investigators stated in an affidavit that Woodward clenched his jaws and fists as he told the story of what happened, and said “he wanted to tell Blaze to get off of him.”

When questioned about Bernstein’s death, police said Woodward appeared nervous, and had scratched hands and dirt underneath his fingernails.

He claimed the dirt was the result of participating in a “fight club” where he fell in a “dirt puddle.”

Investigators ultimately linked DNA evidence between Woodward and Bernstein’s death, and the 20-year-old was arrested after a crime lab found that blood discovered on a sleeping bag in his possession was Bernstein's, the Register reported.

Authorities have not found a weapon.