Marcos Gallegos and Heriberto Villa made their first court appearances Monday both facing two counts of murder and kidnapping charges.
With their arrests, comes more information regarding the gruesome killings of Pederson and Eby back in December.
Jose Pineda and Troy Whalen were both arrested last week in connection to the double murder.
Court documents indicate a fight between Michael Eby and Jose Pineda ended with murder in the garage of a home on Hathaway Street in Yakima.
Police say they were fighting over drugs and money.
"Who owed who, how much money or how much drugs is yet to be determined," said Yakima Police Captain Rod Light.
Investigators say information from Pineda after his arrest last week opened the case even wider.
They say he admitted fighting Eby, but denies killing him. Police say Pineda points the finger at Marcos Gallegos for the actual killing.
Court records of Pineda's statement say Gallegos broke up the fight, "Pulled out a pistol and shot Eby."
Then fired "A couple more times on the ground."
Gallegos is now charged with two counts of first degree murder and kidnapping, along with Pineda and Troy Whalen, for killing Eby and Ryan Pederson.
Both bodies were found in an abandoned car at Yakima Canyon.
But who killed Pederson? Until this point, court documents haven't revealed much about Pederson's death or his suspected killer.
Police now believe a 4th suspect pulled the trigger; Heriberto Villa.
Court documents claim Villa was also there in the garage and, that Pederson was still alive when all four suspects drove to Yakima Canyon to get rid of Eby's body, which was in the trunk.
Police say Villa killed Pederson once they got there.
"Pederson was more than likely the guy hanging out with Eby. They were friends. And sadly enough, found himself in the wrong place at the wrong time," said Light.
Police don't think there's any more suspects out there who were involved in the double murder.
Bail was set at $2 million each for Gallegos and Villa.
Prosecutors tell KIMA formal charges of first degree murder and rendering criminal assistance were filed Monday against Troy Whalen.
Yakima police say Jose Pineda remains in Seattle awaiting extradition.