Nine months after the murder of 13-year-old Marrisa Shen, the person responsible remains on the loose – but police are hoping a new criminal profile will help bring her killer to justice.

On Tuesday, the Integrated Homicide Investigation Team released a number of behaviours they believe the murderer may have exhibited after Shen's death on July 18, 2017.

The killer may have withdrawn from social activities, missed work or scheduled appointments, attempted suicide or displayed suicidal gestures, and shown a keen interest in the media coverage of Shen's murder.

It's possible the person increased or decreased their alcohol or drug use as well, according to the profile.

"If you recognize these characteristics in somebody you know, you need to contact IHIT today," Cpl. Frank Jang said at a news conference.

The criminal profile, which was developed in consultation with the RCMP's Behavioural Science Group, also suggests the unidentified killer might have lived near Burnaby's Central Park, where Shen's body was found, and uncharacteristically avoided the area after her murder.

Profilers believe the killer could have even moved away unexpectedly after Shen's death, either permanently or temporarily.

Investigators have already pored over thousands of hours of video and investigated hundreds of leads, but have yet to identify or arrest a suspect. But Jang said it remains a priority for the homicide team.

"There continues to be a high degree of public interest in Marrisa's homicide investigation," he said. "People haven't forgetting about Marrisa Shen, and I assure you IHIT hasn't forgotten either."

Earlier this year, IHIT revealed it has a list of persons of interest in the case; people believed to have information on Shen's murder.

Jang would not say how many names currently remain on the list, but said it is in constant flux as the ongoing investigation continues.

"I can tell you numerous names on this list have been crossed off," he said. "There's names being eliminated, but there's (new) names that have popped up."

Anyone who has information that could help push the probe forward can contact IHIT, or, if they wish to remain anonymous, Crime Stoppers.