By Mike Hellgren

BALTIMORE (WJZ) — The pivotal trial in the Freddie Gray case will begin Thursday, and there could be some surprises.

Officer Caesar Goodson Jr. is the only one of six officers charged with murder. He was driving the police van through West Baltimore in April of last year when Gray suffered a severe spinal injury.

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WJZ Investigator Mike Hellgren breaks down the big questions surrounding the case.

Lawyers on both sides have filed a number of sealed motions ahead of trial. It all boils down to whether the judge believes Officer Goodson chose to ignore Gray’s injuries and cared less if he lived or died.

Officer Caesar Goodson Jr. is at the center of the Freddie Gray case. As the driver of the van, prosecutors argue he should have made sure Gray was secured with a seat belt, and they claim he failed to get Gray help time and time again.

“The state has to prove beyond a reasonable doubt all the elements of all these charges, and that’s not easy to do,” said Warren Alperstein, lawyer and courtroom observer.

The most serious of the charges was little-known before Baltimore City State’s Attorney Marilyn Mosby shot it into the spotlight.

“Officer Caesar Goodson is being charged with second-degree depraved-heart murder,” Mosby announced in May 2015.

So, what is second-degree depraved-heart murder?

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“It’s simply a form of murder where the state has to prove that a defendant acted with an extreme indifference to human life. Some common examples of that would include shooting at a passenger train into the windows,” said Alperstein.

A critical question — why will medical records play a bigger role in this trial?

Prosecutors have got to lay out when Freddie Gray got injured and could anyone have helped him. The autopsy will be a big part of that.

Another issue — which van stops will play a central role?

Druid Hill Avenue and Dolphin Street is where Officer William Porter admitted Gray asked for help, and where he told Officer Goodson, who did nothing.

Mosher Street and Fremont Avenue is where Goodson alone stopped to check on Gray. We don’t know what was said because Goodson never gave a statement.

How likely is it he will break his silence now and testify? That depends on the strength of the prosecution.

“Did Officer Goodson know that Freddie Gray needed emergency medical assistance? And two, was his failure to provide that emergency medical help the cause of Freddie Gray’s death?” said Alperstein.

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The proceedings start at 9:30 a.m. Thursday.