Prosecutors say Sean Kratz of Northeast Philadelphia helped his cousin, Cosmo DiNardo, kill three of the four young men in 2017. They then allegedly buried the victims' bodies on DiNardo's family farm in Solebury Township.
Kratz walked away from a plea deal earlier this year.
Bucks County Assistant District Attorney Kate Kohler's opening statement painted Kratz as a cold-blooded killer who was on a mission to "kill, rob, burn, and bury bodies" along with his cousin.
Kratz's Attorney, Charles Peruto, painted a decidedly different picture of his client.
Calling Kratz an "idiot" and "slow" with a "tested IQ of 79," Peruto told the jury that his client is not a killer, but rather was too terrified and lacking the intellectual wherewithal to do anything that would have stopped the "lunatic" DiNardo.
Peruto even went after Kratz's original court-appointed defender, Craig Penglase, referring to him in court as a "scumbag" for trying to reach a plea deal instead of trying the case in court.
The trial is expected to last one week and Kratz's attorney says his client will testify.
DiNardo and Kratz were charged with the July 7, 2017 slayings of Dean Finocchiaro, 19, of Middletown Township; Thomas Meo, 21, of Plumstead Township; and Mark Sturgis, 22, of Pennsburg, Montgomery County.
DiNardo pleaded guilty to the three killings and that of Jimi Patrick, 19, of Newtown Township, two days earlier. DiNardo is serving a life sentence.
DiNardo is expected to take the stand later this week.
VIDEO: Cosmo DiNardo arrives at Bucks Co. prison
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