The Austin American Statesman reported Sunday that last year just three inmates were killed. Officials say the increase is puzzling since overall violence, as well as sexual assaults and the number of weapons found in Texas prisons, have all declined in 2012.
Still, this year's tally is a far cry from 1985, when 27 convicts were killed and hundreds more were injured in an outbreak of violence blamed on overcrowding. The state prison system then was less than a third its current size.
Investigations into individual cases have shown the homicides appear to be random acts of spontaneous violence between cellmates with no apparent pattern.
Officials, therefore, aren't blaming gang violence or the fact that more convicts are serving longer sentences. Some facilities, meanwhile, are facing staffing shortages, but those aren't likely the cause either.
"A broad sweep of the indicators is that the system is operating safely and smoothly with fewer problems -- and then this one number," Brad Livingston, executive director of the Texas Department of Criminal Justice, which operates the 111 state prisons, said.
Even as killings have nearly quadrupled, reports of prisoner sexual assaults have dropped from 343 last to 265 through October. Also, weapons-possession cases are down from 1,102 to 837, and serious offender assaults are down from 1,222 to 1,028. Even major uses of force, when prison officials have to get physical to quell disturbances, are down from 7,302 to 5,845.
Most convicts share a cell with another felon, and most of the slayings involved fights with cellmates or other prisoners who lived in their dorm areas. Many prisoners who died were beaten during fights, and several sustained serious injury after hitting their heads on concrete floors. Only one victim was stabbed with a shank, or prison-made knife.
Cellmates involved in deadly fights had been housed together for a range of periods, some for several weeks, others for years. Prisoners are screened before they are assigned cellmates to weed out rival gang affiliations.
The state's shale-oil boom has seen many guards leave for better-paying energy jobs and contributed to more than 2,800 vacancies in prisons statewide. But Livingston said the deaths have occurred at a variety of prisons, not just those that are understaffed.
Advocacy groups say more should be done to prevent prisoner killings.
"So they don't know what's causing all these deaths, and they can't do anything to stop it? That's an abominable excuse," said Terrence Benavides, who has a son and two brothers serving time.
Some officials acknowledge conditions inside Texas prisoners are growing tougher, with more convicts serving longer sentences for violent crimes. Others say that even if staffing levels are sufficient, some guards are new hires and therefore inexperienced.
"Understaffing and lack of training are two big issues right now inside the agency, and both of those can adversely affect supervision," said Brian Olsen, executive director of a correctional employees' union that represents more than 6,000 prison guards.
At the end of October, seven prisons had staffing levels under 70 percent, a threshold when staffing can become an operations issue, according to an internal report reviews by the Statesman.