Military sci-fi novel identification: Man with no memory on trial, main story told as a long flashback; favorite weapon is a shotgun

Question

The book starts with a man on trial, he has no idea why as he is missing a big chunk of his memory.
He fires his attorney, and the court goes with some type of memory retrieval.

We witness what happened in the past: a space ship is boarded, a military campaign on a planet.

There is a comment as to why he prefers the shotgun: it is great for crowd control.

There are several aliens: a group hiding on the mentioned planet and some are also present at the trial.

At the end we learn that the reason why he did not trust his attorney was becouse he was given a subliminal suggestion to not trust a person with a tie of a particular color.

I listened to the story between 2010 and 2014, and it seemed pretty recent at that time. And it is a story set in the future, when Earth and humans are part of the wider galaxy.

EDIT: The weapon is a shotgun and not the bayonet as I thought previously.

Answer 1

I was able to find it through a lucky chance by myself.

It is "Relic Tech", written by Terry W. Ervin II.

The Silicate War has been over for fifteen years, and the tension among the dominant galactic races is growing. Many fear that the Umblegarri, the ancient alien race that ushered humanity into the interstellar galactic community during the Silicate War, have been targeted for conquest by the Crax and their allies.

It’s no longer speculation. The invasion is underway and Kra finds himself strapped to a hospital bed, critically injured and surrounded by hostile corporate lawyers, high ranking military and intelligence officials, ambitious members of the criminal justice apparatus, and an Umbelgarri diplomat. All are demanding answers or their pound of flesh.

Krakista Keesay, a Class 4 Security Specialist, doesn’t have the answers they demand. Why did he sabotage a top secret research facility? What was he doing on a quarantined planet? Why did he set up the civil transport Kalavar for destruction? Is that all? Not even close.

Kra turns to his only option: Allow his brain to be hooked up to an experimental device so that he might prove his innocence.

Or lose his mind.

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