Police have made an arrest in a brutal assault at the Calgary Remand Centre that left a 24-year-old Russian man with permanent brain injuries.

Denis Telyakov was sent to hospital in critical condition after being beaten on August 20th, 2012.

21-year-old Brett Decoux is charged with aggravated assault.

Officers are still looking for 21-year-old Kei Hu Mang; described as Asian, 5’8″ with black hair and brown eyes.

Both Mang and Decoux were former cellmates of the victim, but police say since the incident took place, mang was released from the Remand Centre.

Sgt. Grant Miller says they still don’t have a motive for why Telyakov was assaulted.

“Our victim was not in custody for a long period of time at the Remand Centre. Even though we’ve laid charges, the investigation is not done, and we are still working on exactly why this happened,” he says.

Miller says Telyakov has returned to Russia, but will likely be struggling with his injuries for the rest of his life.