The prosecution decided to indict on a premeditated murder charge a 50-year-old engineer who shot a teenager dead supposedly in self-defence in a car parking dispute in Chon Buri early this year.
Suthep Pochanasomboon has been charged with premeditated murder and carrying a firearm in public over the shooting of Nawapol Peungpai, 17, in Ang Sila tambon of Chon Buri's Muang district.
Four teenagers who were also involved in the dispute have been charged with assaulting officials, conspiring to attack a police officer on duty, and assaulting others causing injuries.
Chon Buri prosecutor Chingchai Chotsaeng defended the decision Monday, saying the charges against both parties involved in the road rage incident are based strictly on evidence, not public opinion.
Mr Chingchai said both parties will have to prepare evidence and witnesses to prove their cases in court.
Speaking to the media, Mr Suthep criticised the decision to indict him on the murder charge, saying he acted to protect himself and his family.
"I was protecting my family from these people who wanted to hurt them and here I am, charged with premeditated murder while those people are charged with physical assault," he said.
"Did I have to wait until they hurt my family or killed someone before we turn to the justice system?" he asked.
Mr Suthep said he would consult with his lawyers on how to prepare his case in court.
Sahaphap Wongthamcharoen, Nawapol's father, said Monday the family would have filed a lawsuit against Mr Suthep if the prosecution failed to act.
He said Nawapol was his only son and he would fight for justice.
The shooting, which stemmed from a dispute over parking on Feb 4, triggered a public debate about a person's right to self defence and who should be held culpable.
Arguments in this case are linked to a series of video clips released online, most of which came from the engineer's vehicle-based camera.
Those who sympathise with Mr Suthep said he was justified in acting in self-defence while others argue he overreacted.
One of the clips shows the engineer stopping his vehicle to seek help from a rescue worker when a van of teenagers followed him and cut in front of his car. The youths flocked to his car.
A fierce argument broke out followed by sounds of a fight and then a gunshot.
A man believed to be Mr Suthep can repeatedly be heard saying "he punched me". A female, who is believed to be his wife, asked "did you shoot him?"
Another video clip apparently from the same camera shows how the argument started before it led to the shooting.
It shows the van, packed with teenagers, double-parked and blocking the man's car.
The driver, who is believed to have been the engineer, and a woman express their anger over the situation.
The man asks the woman to hand him a gun kept in the car. Soon afterwards a full-blown argument breaks out.
Office of the Attorney-General spokesman Somnuek Siangkong said public prosecutors considered the case carefully and fairly, based on the evidence.