At the heart of this case is toxicology and proper lighting.
Prosecutors plan to present toxicology test results for alcohol and drugs to a grand jury next month.
Witnesses and avid boaters have questioned whether there was enough lighting on the barge in the first place.
Jojo John showed up at Orangetown Justice Court in a neck brace, and at some points cringed with pain.
This is the first time we're seeing the 35-year-old Nyack man since he took five friends on a power boat from Piermont to Tarrytown nearly three weeks ago.
The boat crashed into a Hudson River construction barge near the Tappan Zee Bridge.
A soon-to-be bride and best man both died, just days before the wedding.
"Mr. John and his family will not be making statements, but they do what to extend their condolences to all of those involved," said David Narain, John's attorney.
Lindsey Stewart's parents spoke to Eyewitness News just hours after the accident and are now asking for privacy as they mourn the death of their daughter.
Her fianc? Brian Bond was also badly hurt.
And their best man, Mark Lennon, drowned.
The defendant's legal team explained their goal is simple in this case: find out exactly what caused the July 26th crash.
"We are doing our own independent investigation. We are looking at the barge its lighting we're speaking to witnesses, residents in the area, boaters who know these water ways. Eyewitnesses. We're asking for anyone with information please contact us," Narain said.
Jojo John is due back in court on September 25th.
He's facing felony charges of vehicular manslaughter.
If anyone has any information on the crash they are asked to contact firstname.lastname@example.org.