As a tribute to the recent tragic death of his "Glee" cast mate Cory Monteith, Darren Criss looked somber wearing a black ribbon on the lapel of his gray suit while attending the screening of his new movie, "Girl Most Likely," US Weekly reports.

A black ribbon can signify remembrance or mourning, and a source told US Weekly that Criss looked rather sad and somber" during the otherwise celebratory event. "He only smiled when he was posing for photos and obviously wanted to get off the carpet as soon as possible."

Though Criss attended the film premiere, he canceled his July 16 appearance on "Live With Kelly & Michael" soon after the death of his friend and co-star Monteith was announced. A source told US Weekly that Criss dedicated a song to his friend during his Up Close and Personal encore engagement with "Glee" co-star Matthew Morrison on July 14 at 54 Below in NYC.

Morrison told the crowd before the show started: "'We lost a great young man too soon.':

"He said Cory was a beautiful person," an insider reported. Morrison also canceled his performance scheduled for "Kelly & Michael" on July 18 in the wake of Monteith's death.

Cory Monteith was found dead in his Vancouver hotel room at the age of 31, the cause for his death yet unknown. The British Columbia Coroner's office recently stated that an update on the "final cause of death might be several days or even a couple of weeks" coming.

Monteith was known for his struggles with addiction to drugs and alcohol, and made no secret about it while he strove to recover from the illness. His girlfriend and "Glee" co-star Lea Michele was right by his side the entire time, and now the actress is "devastated" and has asked for privacy from fans and the general public during this difficult time.

Click here to see a photo of Darren Criss wearing a black ribbon to honor Cory Monteith while attending the film premiere for "Girl Most Likely."