Bradley Vincent Balzan was 20 when his life was cut short during a proactive police operation in the western Sydney suburb of St Marys days before Christmas 2020.

A coroner has been tasked with examining standard practices and procedures for proactive police teams tasked with speaking with people in public who are not reasonably suspected of any crimes.

On Tuesday, as a three-week long inquest into the death wrapped up, Mr Balzan's parents described their son as warm, loving and humorous.

They recounted how his death had destroyed their lives as well as the life of a young man with his future ahead of him .

"We ask why? Why were we put in this position in the first place?" father Adam Balzan said in a statement read by Bradley's aunt Jacqueline.

The family were now deprived of future "firsts" the young man could have looked forward to, like going overseas, getting married and having a child.

Mr Balzan was "a young man just starting on the cusp of adulthood" who "had the world at his feet", Lidcombe Coroner's Court heard.

Mother Belinda Collins said the 20 years she spent with her son were the best of her life.

"Bradley was the kind of person you wanted in your life," she said.

"He gave me reason to want to live."

Kind, caring and non-violent, Bradley had talked about being a national park ranger or joining the army or police, the inquest heard.

The last time Ms Collins contacted her son was by text on December 22, when she asked what time she could pick him up on Christmas Day.

"I not only lost my son that day, I also lost my best friend because of a situation he did not start or want to be part of," she said.

Speaking to reporters outside the inquest, Bradley's uncle Troy Balzan called for a royal commission into the shooting, which occurred despite the 20-year-old not being suspected of a criminal offence.

Giving evidence earlier on Tuesday, NSW Police Assistant Commissioner Scott Whyte defended a lack of specific training for proactive police officers.

He said all officers had to interact with the public and were taught how to do so without escalating the situation.

"We do train around it, it's not like we've never played in this space," he told the inquest.

"But certainly it's an area, in my view, (where) we need to do more."

He denied suggestions most people would not know they had a right to simply walk away if stopped by police before a reasonable suspicion had been raised.

State Coroner Teresa O'Sullivan asked what the downside would be if a police officer speaking to someone was required to say that person was free to leave if they wanted.

"I'd be surprised if it's not being said," Mr Whyte said.

Findings and recommendations will be handed down at a later date.

Australian Associated Press