Two hours after he began beating Adam Kargus to death, Anthony George — supposedly blacked out and unaware of what he was doing — heads to his jailhouse cell window.

With one hand, he gives a thumbs-down through the window.

With the other, he makes a slashing motion across his throat.

The message had to be clear to the other inmates in Unit 6 Left of the Elgin-Middlesex Detention Centre, the provincial jail in London. They’d seen or heard it all.

Exhibits from George’s preliminary hearing, for his murder trial, released Wednesday by the Superior Court of Justice include video excerpts from Oct. 25, 2013, and the night Kargus was killed, Oct. 31.

George, 32, pleaded guilty to second-degree murder two weeks ago, after a two-day trial where only a brief statement of facts was read and one exhibit entered.

He was sentenced last week to life in prison with parole eligibility in 10 years.

George, from Kettle Point, had insisted for four years he wasn’t guilty in the death of Kargus, a Sarnia man, because he had blacked out.

After watching the video, he realized he was guilty, George said.

That’s no wonder.

Although the video surveillance shows the two men through a cell window, sometimes appearing only as a grotesque silhouette mime, it’s clear at many moments what is happening: One man is killing another.

For that reason, and in the interests of community standards, The London Free Presshas decided not to run video excerpts of the killing.

But in the interests of keeping an accountability spotlight on EMDC, a frequent flashpoint for troubles in Ontario’s correctional system, The Free Press is providing an account of what can be seen on the video excerpts.

They begin Oct. 25, 2013, with scenes of George applying chokeholds to Kargus four times that day.

Once, Kargus goes limp. Two other times, he appears to pass out.

The video excerpts begin again the afternoon and evening of Oct. 31.

In one of the most disturbing excerpts, for what is says about EMDC operations, George appears at the “cage,” the meshed doorway where correctional officers can stand and observe a unit, about 3:46 p.m.

From other exhibits, it’s known what George and the officer discuss. George is wearing a shirt with a jack o’lantern and asks the officer if she likes it. George says, trick or treat, and the officer replies, there are no treats so he’d have to perform a trick.

George marches over to Kargus and puts him in a chokehold. Another officer, on the range, approaches.

No one does a thing while George puts Kargus in the chokehold, his knees buckling.

It’s not clear if the officer on the unit talks George into stopping. Soon after, the officer puts the two men into Cell 3.

The start of the assault appears on the video surveillance at 7:56 p.m. George strikes Kargus with his left hand, then twice with his right.

Kargus hunches over and appears to be defending himself with his hand.

It doesn’t help.

In that excerpt, and others at 8:16 p.m., 8:26 p.m., 8:30 p.m. 8:32 p.m., 8:40 p.m. and 8:51 p.m., the video shows a constant assault, punches, chokeholds, kicks and stomps.

When he stomps on Kargus, George sometimes braces his hand on the cell wall to give himself leverage.

Early in the assault, Kargus has his hands together as if he’s pleading for mercy or help from others in the unit.

After the assault, George can be seen cleaning the walls and window of his cell.

At 10:02 p.m., he gives the thumbs-down and the throat-slashing gesture.

The next morning, video shows George coming out of his cell, calmly waiting for a correctional officer to leave the unit.

He takes a pile of what appears to be sheets out.

Then he gets help from other inmates to help him clean up, while he drags the body of Kargus into the showers.

Watch for more coverage of the case at lfpress.com and in Saturday’s London Free Press

rrichmond@postmedia.com