James Rackover is the first suspect to be tried in the murder of 26-year-old Joey Comunale.
He's also charged with concealing a human corpse and tampering with evidence.
Rackover and Lawrence Dilione are accused of killing the Hofstra graduate in 2016, before burying him in a shallow grave in New Jersey.
Authorities say Comunale attended a party at Rackover's apartment on November 13, where police said he was stabbed 15 times in the chest during an argument.
His father reported him missing the next day, and his body was found in a wooded area down the Jersey Shore in Oceanport two days later.
As testimony got underway, authorities revealed pictures of the shallow grave. Several of Comunale's relatives, including his parents, sobbed through the testimony given by investigators with the Monmouth County Prosecutor's Office, each picture revealing more of the body.
Rackover's defense attorney said in his opening statement that it is not his client but Dilone who is responsible for the murder. But prosecutors say Rackover showed a "monstrous indifference for human life."
"The defense here is that they can't prove beyond a reasonable doubt that my client acted in concert with Mr. Dilone, causing the death of Mr. Comunale," said defense attorney Maurice Sercarz.
Witnesses described a hard-partying night that included alcohol and cocaine. The most serious charge is second-degree murder, which means Rackover would spend the rest of his life behind bars.
Rackover is the surrogate son of celebrity jeweler Jeffrey Rackover, whose clients include Oprah Winfrey and Jennifer Lopez.
Dilone will be tried early next year. A third man is also charged with helping in the cleanup effort but not the actual killing.
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