When 18-year-old Griffen Kramer — the son of NFL great Erik Kramer — turned up dead after a party on Halloween weekend, officials at Thousand Oaks High School suspected alcohol poisoning was to blame.

But the L.A. County Sheriff's Department made a sweeping effort this morning to hold others accountable for the tragic accident.

KTLA reports that deputies, search warrants in hand, entered six different homes before making five arrests in connection with Kramer's death. The most severe charges were handed to 19-year-old David Nernberg:

Involuntary manslaughter.

Kramer was found lifeless on the morning of Sunday, October 30, at Nernberg's house in Agoura Hills.

Nernberg's player profile on MaxPreps.com lists him as former student at Agoura Hills High School, located one town over from Kramer's campus. He played on the school's varsity football team in 2010-11, manning both the defensive and offensive lines. (Kramer was a backup quarterback for Thousand Oaks, but reportedly attended Agoura Hills for the first two years of high school.)

The suspect's Facebook indicates he may have moved on attend college at UC San Diego. He's friends with Kramer online as well.

The four other arrestees — two juveniles and two adults — were charged with misdemeanor offenses.

R.I.P. Griffen Kramer; Credit: CHUCK KIRMAN/Ventura County Star

R.I.P. Griffen Kramer; Credit: CHUCK KIRMAN/Ventura County Star

According to KTLA, sheriff's and coroner's officials believe Kramer overdosed on some kind of drug that Saturday night — possibly heroin. He spent part of his sophomore year in rehab for substance abuse.

Nernberg is believed to have panicked, failing to seek much-needed medical attention for his friend after finding him passed out. From the news report:

The night before Kramer was pronounced dead, detectives told KTLA that Nernberg was partying with Kramer at a park and at some point, Kramer became unconscious and was in need of medical attention.

Authorities say that's when Nernberg put Kramer into his car and started driving around, calling his friends and asked what he should do.

Eventually, Nernberg took Kramer to his house, dragged his body inside and left him there until the following morning where he was found dead.

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