A pilot accused of killing three people after the plane he was flying crashed will stand trial. Investigators say Brent Caldwell was at the controls when his plane crash-landed in Grand Lake, killing the three passengers on board. A Delaware County judge ruled there is enough evidence to try the Pryor native. The News On 6’s Chris Wright reports Caldwell was flying without a pilot's license, and after Monday’s hearing, he is still facing first degree manslaughter charges.

Brent Caldwell was the only person who survived after his single-engine Viking went down near Disney in December. The three other passengers, 15-year-old Mariano Carlos, 20-year-old Eduardo Robles and 33-year-old Campos Gonzalez, were killed.

Caldwell did not have a valid pilot's license, and the Oklahoma Highway Patrol said he was under the influence of alcohol at the time of the crash. A recent toxicology report though determined that Caldwell was not drunk. Still, a Delaware County judge decided that because Caldwell lacked a license, there is enough probable cause in the case.

"The deaths of three individuals, that's what we needed to prove for the preliminary hearing, said Delaware County Assistant District Attorney M. Bryce Lair. “And the court apparently agreed with us,"

Caldwell's Pennsylvania Aviation Accident lawyer, Winston Connor, says he 'respectfully disagrees' with the decision. He says the state has admitted the Viking did experience mechanical failure before going down. Connor tells The News On 6 that because there was no pilot error, his client can not be charged with manslaughter.

The Delaware County Assistant District Attorney believes this will be a unique trial, simply because there is no real precedent in the case. He says that no one in the state has ever been tried for causing the deaths of passengers while flying without a license.

"The underlying misdemeanor in this case is an airman certificate, or what is commonly referred to as a pilot's license. That has not been done in the state of Oklahoma to my knowledge," said Lair.

Caldwell's lawyer points out that the family of the victims would like to see all the charges against the pilot dropped. He says the district attorney is the only person who wants to pursue jail time.

A judge will set a trial date for Caldwell on May 9th.