Homicide investigators are still working to track down Marrisa Shen's murderer, and have asked the public for any video taken at the 13-year-old's vigil or funeral. 

Cpl. Meghan Foster of the Integrated Homicide Investigation Team said video from either event could help push the month-old case forward, but she stopped short of suggesting the killer might have been in attendance.

"We don't know if they attended," Foster said. "This case has drawn attention nationwide and because of the attention it's drawn [the videos are] something we'd be remiss not to ask for."

The vigil was held in Burnaby's Central Park on July 22 and the funeral was held at Mountain View Cemetery in Vancouver on July 28. Police have urged anyone with video or even pictures to share them.

After weeks of investigation, IHIT has made some progress; Foster said the homicide team is in the process of following up on nearly 200 tips related to Shen’s murder, and has identified more than 90 persons of interest.

Persons of interest are not suspects, Foster noted, only individuals who might have information relevant to the case. The 90 or so who have been identified know who they are.

IHIT has also managed to narrow the timeline for Shen's killing; surveillance video has been obtained showing the teenager walking on the south side of Central Boulevard and crossing McKaye Avenue at 7:38 p.m. on July 18, around five hours before her body was discovered in Central Park.

Previously, the last known sighting was at 6 p.m., when Shen was seen leaving her family's apartment in dark shorts and a dark T-shirt.

On Wednesday, Foster also confirmed for the first time that Shen was likely killed in the park, and not slain elsewhere and transported.

"It should be noted that this does not change our belief that Ms. Shen's homicide was random," Foster added.

Anyone with information on the case is asked to call the IHIT tip line at 1-877-551-IHIT, or Crime Stoppers at 1-800-222-TIPS.