A former Mountie is facing a perjury charge over his testimony at the trial of a mother convicted of killing her own child.

Retired Staff Sgt. Ross Spenard is accused of lying when he appeared as a blood spatter analyst at the trial of Charlie Rae Lincoln in 2009.

Spenard was a member of the national police force for 32 years before retiring last year in the midst of a code-of-conduct investigation.

His retirement put an end to the RCMP's internal investigation but the Crown filed a formal complaint with the Vancouver Police Department, prompting a criminal investigation.

"In May 2009, Spenard allegedly perjured himself while testifying in B.C. Supreme Court in the capacity as an expert witness in bloodstain pattern analysis during the murder trial Regina v. Lincoln," Vancouver police said in a statement released Tuesday announcing the charge.

"The perjury became evident during the course of the trial through disclosure requests sought by defence counsel. While under cross-examination, Spenard admitted to not telling the whole truth in his earlier testimony."

After the judge advised the jury to ignore Spenard's evidence, Lincoln was found guilty of the July 2006 stabbing death of her two-year-old daughter in Bella Bella, B.C.

Spenard was also a member of the forensic investigation team that combed serial killer Robert Pickton's farm, and he appeared as one of the hundreds of witnesses called at Pickton's murder trial.

"All (Spenard's) files did go through a file review, anything that he worked on. There were no concerns out of that," said RCMP Sgt. Rob Vermeulen.

He could not say how many files were reviewed but said it was a lot of work, because there are only 10 such blood-spatter experts across the country.

"You have to get someone who is knowledgeable and an expert in order to do the file review. It was a time consuming process," he said.

The review started shortly after the allegations were made against Spenard, said Vermeulen.

Spenard was also involved in about 30 other cases due to come before the court, said Neil MacKenzie, a spokesman for the B.C. Crown prosecutors office.

"Steps taken also included assessing whether the potential evidence he could provide was a necessary part of the Crown case," MacKenzie said.

"In some cases the police reassigned the files to other expert analysts for review so that they would be able to testify in place of Staff Sgt. Spenard."

MacKenzie said the Crown also had to make sure that was disclosed to defence counsel in each case, so lawyers would be aware of the concerns raised in the Lincoln prosecution.

He couldn't say if any cases were delayed because of the allegation against the former officer.

"It's certainly been a painstaking process just to make sure the cases were identified. The review didn't raise concerns with respect to Staff Sgt. Spenard's evidence in other areas of forensic expertise."

MacKenzie said there was also no concern with Spenard's work on the Pickton trial.

Lincoln has filed an appeal of her second-degree murder conviction.