ST. JOHN'S, N.L. -- A lawyer for Don Dunphy's daughter grilled the lead RCMP investigator into the police killing Thursday over what he called major shortcomings in the probe.

At the inquiry into Dunphy's 2015 death, lawyer Bob Simmonds questioned Cpl. Steve Burke about how the RCMP never tried to lift fingerprints from a bullet found in Dunphy's .22-calibre rifle.

Nor did the RCMP order a test to detect blood or other DNA on the rifle, found at Dunphy's feet at his home in Mitchell's Brook, N.L.

Simmonds suggested significant gaps have been left in the evidence, but Burke said those issues didn't affect the overall results of the lengthy investigation.

"I stick by those decisions," Burke said.

Const. Joe Smyth of the Royal Newfoundland Constabulary shot Dunphy once in the chest and twice in the head after he says he aimed a rifle at him on Easter Sunday.

The RCMP found it was an appropriate use of force. Simmonds represents Dunphy's daughter, Meghan, who has questioned the quality of the RCMP probe.

Burke did say Thursday that if he had it to do again he'd seek a checklist of procedures for officer-involved shootings.

He confirmed that it wasn't until after the scene was released that he thought of consulting such a list, such as one used by Nova Scotia's Serious Incident Response Team.

This is despite the fact Burke had never handled such a case before.

Simmonds also asked Burke about deleted Blackberry direct messages on Smyth's phone that the RCMP just recently retrieved and disclosed to the inquiry.

They include a message Smyth sent to a friend the day before the shooting indicating he might have to arrest a "lunatic" who was "threatening" then-premier Paul Davis.

Smyth testified last month -- before those messages were retrieved -- that he never considered Dunphy a threat and went to his home to "build a rapport."

Smyth, a member of Davis's security detail, made the solo trip into RCMP jurisdiction after staff in Davis's office flagged a single post on Twitter. Dunphy, 59, was an advocate for injured workers who often aired his frustrations with workers' compensation on social media.

Smyth also told the inquiry under oath last month that he did not get advice or input on his notes before giving a statement to the RCMP the day after the shooting.

But more of those deleted messages show he conferred with RNC Sgt. Tim Buckle about wording.

Commission staff have not confirmed if Smyth will be recalled to answer those discrepancies.

Simmonds was perhaps most incredulous Thursday that the homicide scene was released two days after the shooting without Burke's immediate knowledge.

"You hear about that the morning after it happened," he said. "How can that happen?"

Burke replied that he always understood the scene would be released after the autopsy was completed, which was done on April 7, 2015.

Two medical first responders have testified police photos don't match what they saw just after the shooting.

Smyth's lawyer, Jerome Kennedy, said Simmonds' questioning exposed his client to unfair speculation.

He had Burke confirm that Smyth co-operated at every stage of the investigation, and told Commissioner Leo Barry that Smyth would assist if more forensic work can be done.

"He will provide his fingerprints. He'll provide his DNA. Let's get some of the testing done."

Commission co-counsel Kate O'Brien said there will be forensic evidence to come on whether such tests can occur.

The RCMP said no fingerprints could be lifted from the rifle as its surfaces were too rusted, pitted and old.

Simmonds asked if it had been sent to a more advanced forensics lab than the standard testing done in Ottawa.

"I understand they can lift prints from human skin," Simmonds said.

Burke said the rifle was not sent for advanced analysis.

The inquiry is hearing from more than 50 witnesses into March.

Barry will not make findings of criminal or civil responsibility but any new evidence could be investigated by police.