Mark Grant, seen here in a court sketch from Jan. 17, was interviewed by police in 1984, but was not considered a suspect in Candace Derksen's death at the time. He was later arrested in 2007. (CBC)A retired high-ranking Winnipeg police officer says he didn't view Mark Edward Grant as a suspect when he interviewed him in 1984 while investigating the disappearance of 13-year-old Candace Derksen.

Grant, 47, is now on trial for first-degree murder in Candace's death.

She disappeared Nov. 30, 1984, and her bound and frozen body was found in a brickyard shed Jan. 17, 1985.

Menno Zacharias, a detective sergeant in the youth division in 1984, said when he talked to Grant, it was to check out claims by Grant's girlfriend that she had seen Candace after she disappeared.

'Has not seen Candace. Didn't know Audrey knew her.'- Notes from police interview with Mark Grant in 1984

The case had been making headlines for more than a week when he went to the Remand Centre to speak with Grant on Dec. 10. Grant had been taken into custody for being unlawfully at large.

"The prime case I was working on, along with the rest of the youth division, was the disappearance of ... Derksen," said the retired officer, who eventually rose to the rank of deputy chief prior to retiring in late 2008.

"He wasn't a suspect in the case and he was co-operative."

Audrey Fontaine, who was Audrey Manulak in 1984, a troubled 14-year-old runaway, has already testified about her relationship with Grant, who was in his early 20s at the time. She told court on Friday she saw Derksen coming out of a Talbot Avenue store not long before she vanished.

Candace Derksen was 13 when she disappeared after school on Nov. 30, 1984. (CBC)Since Grant wasn't a suspect, Zacharias said he didn't take a formal statement from him. All the officer has now are his notes of the interview, which he read to the court.

"Has not seen Candace. Didn't know Audrey knew her," he read.

Police also had questions about girl's clothing found in a concrete dugout in the CPR railyards. It was a hideout Grant used after he initially escaped custody and Manulak shared it with him for a night or two. The court heard earlier that "I love you Mark" was scrawled in chalk on one of the bunker's cement walls.

But when questioned, Grant told police that "only he and Audrey stayed there," Zacharias read to the court.

Suspect's jeans tested in 2007

Earlier Monday, the jury heard more about how the case continued to be investigated years after Candace's death.

Tod Christianson, an RCMP forensic scientist, received articles of clothing and other items from Winnipeg police for DNA testing in February 2001.

It was run through the RCMP databank at the time and did not produce any matches. But at the time, he said they did only nuclear DNA testing. There are two other methods.

The last witnesses to testify Monday brought the case into 2007, the year Grant was arrested.

Sgt. Brian Chrupalo of the cold-case unit asked Sgt. Robert Russell of the identification division to take a blood sample from a pair of jeans taken from Grant, who was a complainant in another case.

The samples were then sent to Molecular World Inc. in Thunder Bay, Ont., the first accredited lab in Canada to do mitochondrial DNA testing.

Mitochondrial DNA, also known as mtDNA, is passed down from mother to child and allows a person's maternal lineage to be traced.

Tuesday, jurors hearing the case are expected to hear testimony from as many as six of Grant's maternal siblings.

With files from the CBC's James Turner