SAINT JOHN, N.B. -- A New Brunswick politician who may have caught a fleeting glimpse of Richard Oland's killer on July 6, 2011, has told a court there's little he recalls from the night of the murder.

"I've racked my brains the last couple of months," Liberal politician Gerry Lowe told Dennis Oland's murder trial on Tuesday. "I've thought and thought ... It has been so long. Eight years is a long time."

Lowe, who represents Saint John Harbour in the New Brunswick legislature, was the first witness for the defence as Dennis Oland's trial moves into its final stages. Dennis Oland, 51, is charged with the second-degree murder of his wealthy businessman father, Richard, in his uptown Saint John office.

Directly across the street from the building where Oland's office is located is Thandi's restaurant. Lowe told the court he probably visits the eating establishment "300 or 400 times a year."

Lowe said that while he cannot recall for sure what night it was, what the time was or what the person looked like, "I know I saw a man come out the door (from the Oland office) and walk to the left towards King Street."

The court already knows from video shown earlier at the trial that Lowe was at Thandi's restaurant on the night of July 6, 2011 between 7:40 p.m. and 8:35 p.m.

The question is, did he see the person on that night or during one of his other many visits to the restaurant?

The issue is critical to Oland's defence. He has long been described as the last known person to have seen his father alive. The prosecution maintains he bludgeoned his father to death between 6 p.m. and 6:30 p.m. during a private visit to the office.

If Lowe saw a person leaving Oland's office at a later time, between 7:45 p.m. and 8 p.m., it opens the door to murder by someone other than Dennis Oland.

The accused was caught on security video shopping at Rothesay, on the outskirts of Saint John, at around 7:30 p.m.

Following Lowe's testimony, defence lawyer Alan Gold called Saint John police officer Stephen Davidson to the stand. Davidson interviewed Lowe in May 2015, prior to Oland's first trial -- although he did not testify during that trial.

Dennis Oland was found guilty by a jury in 2015 but that verdict was set aside on appeal and a new trial ordered.

Davidson told the court he talked to Lowe to follow up on earlier police interviews with him in 2011. He said Lowe recalled a photo shoot at Thandi's on the night he believes he saw the mysterious man -- July 6, 2011.

"That was the night he believed he saw the person exit the building," Davidson said.

There were at least two people who came and went from the office building that night, from the ground floor printing shop. One of the men went out for a smoke and Lowe said it is possible that could have been the person he saw.

But he was sure it was not a customer who arrived at the printing shop around 8 p.m. that night.

Later in the day, retired RCMP forensics officer Brian Babin testified about one, faint footprint found on the floor of Richard Oland's office.

Several pairs of shoes were offered for examination by Babin, including some taken from Dennis Oland's home, but all were excluded as possible matches.

Babin told the court he could not say when the impression was made, meaning it could have been on the floor before the murder.

"In summary, no footwear impressions could be identified," Babin said.

Dennis Oland, the star witness for the defence, is expected to be called to the stand as early as Wednesday.