Dustyn Frolka (Handout photo)

Dustyn Frolka (Handout photo)

ST. JOHNS, Mich. (WWJ/AP) – Authorities have charged two 18-year-olds and a 16-year-old with first-degree murder and armed robbery in the slaying of a Michigan State University student who was found unconscious along I-69 near East Lansing.

READ MORE: Michigan Matters: Pistons’ Rob Murphy on Helping His Hometown

The Lansing State Journal reported 19-year-old Dustyn Frolka of Owosso was beaten with brass knuckles.

A judge on Monday ordered Samantha Grigg, Tyrel Bredernitz and Brendon Heim jailed without bond at their arraignment in Clinton County District Court in St. Johns.

Grigg is a senior at Saline High School near Ann Arbor and Bredernitz is a Saline High graduate. The 16-year-old Heim says he dropped out as a sophomore.

The trio was arrested on Saturday in Saline, near Ann Arbor, the Lansing State Journal reported.

Frolka was a sophomore at Michigan State.

READ MORE: Ribs RnB Music Festival Kicks Off This Weekend In Downtown Detroit

According to police, a passerby called 911 on Feb. 15 at around 10:30 p.m. after seeing Frolka  lying on the freeway near the East Lansing exit. When officers arrived, Frolka was partially clothed and was in “respiratory distress.”

Frolka had abrasions consistent with hitting the pavement but no obvious wounds, investigators said.

He was  rushed to Lansing’s Sparrow Hospital where he was pronounced dead. Police said they were awaiting toxicology results to determine what killed him.

Frolka was a talented rapper but “had been on kind of a downward spiral” since the fall, according to fellow hip-hop musician Blake Selby. Selby told the newspaper that he signed Frolka to the Lansing-based label he runs, though they later parted ways.

MSU police arrested Frolka for cocaine possession on Jan. 31, according to court records. He was then kicked out of his dorm because of actions that were deemed a threat to the safety of other residents, the university said.

According to Frolka’s Twitter page, the student mentioned drug use in the hours before his death, tweeting “I’ve never done DMT and tonight is about to change ****.” DMT acts as an intense hallucinogenic drug when ingested.

MORE NEWS: Judge Says Michigan Gov. Whitmer Won't Have To Testify In Abortion Lawsuit

TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.