VIDEO: Robert Cotton was killed by Pete Van Winkle in Phoenix Arizona's Maricopa County Jail, Run by Sheriff Joe Arpaio in an alleged Aryan Brotherhood dispute.

Relatives of a Maricopa County jail inmate killed during a brutal, 19-minute assault caught on surveillance video are asking how the slaying could have happened in a facility considered one of the most secure in the West.

The video obtained by The Arizona Republic and other news sources shows inmate Pete Van Winkle, 26, jumping up and down on what appears to be the lifeless body of Robert Cotton, 28, before dragging him out to a second-floor walkway and attempting to hoist his body over a railing.

Cotton's brother, Scott Appelbe, said that such a beating could take place means the Sheriff's Office needs to reconsider its approach. He said he is speaking out in the hopes that public pressure will force the Sheriff's Office to change procedures at the facility.

"I don't want you or me or anyone else to have to deal with this again," Appelbe said. "It was hard enough for me to bury my brother."

Sheriff's officials said Wednesday that the death could not have been prevented and that they reviewed jail policies and procedures after the death and found no reason for a change.

Officials say the detention officer on duty in the control tower of the closed-custody unit, whose job it was to monitor the video cameras during the time of the May 1 slaying, did his job exactly as he was trained.

"After reviewing this incident, we are confident this homicide could not have been prevented," said Jerry Sheridan, the county's chief of detention. "It was never in full view of the officer."

Prosecutors are seeking the death penalty against Van Winkle.

On a Wednesday tour of the unit where the killing took place, sheriff's officials acknowledged that the measures in place at the state-of-the-art, 4-year-old Fourth Avenue Jail aren't sufficient to prevent inmates from killing each other. The measures include cameras, guards and procedures designed to keep inmates separated from one another.

"(Spotting the assault) would have had to be almost serendipitous," said Lisa Allen, a sheriff's spokeswoman. "There was nothing to indicate anything was wrong."

The slaying

The May attack happened in an upstairs cell of the jail's closed-custody unit," where inmates with a violent history, mental illness or protective orders are housed.

Cotton had been in and out of prison for much of the past decade. Van Winkle was jailed for theft offenses before he was arrested in early March on suspicion of attempted murder.

That evening, prisoners in the area were on their daily four-hour release from their cells. Shortly after 8 p.m., the two men entered Van Winkle's cell. Jail cameras captured what happened, starting at 8:15 p.m.

Video shows Van Winkle apparently choking Cotton, jumping up and down on what appears to be Cotton's lifeless body and slamming his head against the floor.

Van Winkle then drags the body out to the upper-level concourse, leaving a trail of blood. Van Winkle repeatedly looks into a jail-surveillance camera before attempting to hoist Cotton over a railing and onto the first floor. The footage shows another inmate walking by the cell twice.

The video next shows Van Winkle lying down on the lower-level floor; face first, with his hands behind his back, as if he is waiting to be arrested. Soon, officers arrive and take him into custody. The sequence ends about 8:34.

Cotton was rushed from the facility and later pronounced dead.

Cotton's family filed a $2 million notice of claim with Maricopa County officials last month and could file suit against the Sheriff's Office if county administrators don't respond by early November.

On Wednesday, the jail's surveillance video gave the world a chance to see how the assault unfolded.

But sheriff's officials said the 19-minute sequence from a single camera offers a far different perspective from what the officer on duty had that night.

In the control tower

Sheriff's officials said the detention officer in the control tower was one of three on duty in the closed-custody unit that evening.

He was in the tower monitoring inmates who had been released from their jail cells for free time that evening. But sheriff's officials said detention officers in the towers had other responsibilities. A sheriff's report about the incident indicates the guard on duty in the tower placed a phone call about training in addition to logging data into a computer and electronically opening and closing doors.

The two other officers on duty were on a 20-minute walk through the unit. The tower officer's primary responsibility, in addition to his other duties, was to keep an eye out as the detention officers made their rounds.

The officer uses six screens, each about the size of a compact-disc case, to monitor the 12 cameras.

Sheriff's officials said the officers typically do not cycle through all 12 cameras. Instead, they use them to monitor other officers and inmates as they move around the unit.

Watching the inmates

The attorney for Cotton's family questioned whether officers should have noticed Cotton wasn't in the right area of the unit during the break period. During other times, he said, they watched him so closely that they knew which restroom he usually used.

In the minutes before the slaying, Cotton and Van Winkle can be seen talking in a lower-level recreation area with other inmates, before Cotton rises and walks up to Van Winkle's second-floor cell.

Cotton was given a cell on the first floor of the 36-cell unit because of a medical condition, but Sheridan said Cotton frequently used the second-floor restroom. Cotton's movement to another floor in the closed-custody facility wouldn't have raised any concerns, Sheridan said.

Joel Robbins, who represents Cotton's family in their legal fight with the county, said that corrections officers knew where Cotton went to the restroom shows they paid close attention to the inmates.

"It's obvious they should be watching him when he doesn't go in the bathroom so that's another sign they should be worried," Robbins said. "That's in essence blaming the victim saying there's only so much we can do.

From another camera angle, viewers can see the corner of Van Winkle's cell where much of the beating takes place. The footage, obscured by the cell door and wall, shows what appears to be the two men struggling before Van Winkle gets the upper hand.

Sheridan said the officer in the tower that night would not have known to focus one of the 12 cameras on Van Winkle's cell unless he'd seen something amiss.

With Cotton a frequent visitor to the second-floor men's room, and Van Winkle ostensibly spending his free time in the cell, the detention officer had no cause for alarm and was focusing his attention on the two other officers conducting cell checks, Sheridan said.

"He was following our policies and procedures," Sheridan said.

Policies and procedures that allow for a slaying in one of the county's most secure facilities clearly aren't adequate, Robbins said.