CALGARY - Minutes after arriving at the jail, a Calgary Remand Centre inmate was beaten so badly he is unable to testify about his ordeal.

That fact emerged Tuesday as part of a court exhibit entered into the aggravated assault trial of Jeremy Clifford Thomas.

And one fellow inmate told court it was Thomas who inflicted the serious brain injury to Mitchell Byron Tilden which has rendered him incapable of testifying.

Joseph Mendiuk said he watched at Thomas attacked Tilden on the jail's Unit 1 last Dec. 2.

"I was horrified at the spectacle I observed," said Mendiuk, rejecting suggestions by defence lawyer Mitch Stephensen his co-operation was to get him transferred from Calgary.

"I thought I would do the right thing once in my life and testify," said Mendiuk, denying he fingered Thomas so he could be sent back to Edmonton remand.

"I saw the guy's face when he was stomping on the man's head," said Mendiuk, who is serving a 10-month sentence at the Calgary Correctional Centre.

"Later on I saw them taking him from his cell," he said, identifying Thomas.

In an agreed statement of facts put in by Crown prosecutor Rajbir Dhillon, court was told Tilden was badly injured in the Dec. 2, attack by two fellow inmates.

Tilden, 30, had been admitted to the remand centre that afternoon and was placed on Unit 1 just 22 minutes before he was assaulted, the statement said.

He was left in a coma, from which he has since recovered, and suffered brain damage.

"As a result of these injuries, Mr. Tilden does not have the mental capacity sufficient to give evidence," the statement read.

Meanwhile, Mendiuk's testimony had to be interrupted so a Sheriff's guard could testify about an exchange between Thomas and the witness in cells during a court break.

Everald Wright said a yelling Thomas swore at the witness, called him a "goof" and threatened to "get him."

The trial continues Wednesday.

kevin.martin@sunmedia.ca