Prison reform advocates got a big victory Aug. 18 when the U.S. Department of Justice (DOJ) announced it would no longer use private prisons to house federal inmates. While the decision is limited in its scope, it will affect 13 privately run correctional facilities and roughly 22,000 inmates.

"This is the first step in the process of reducing — and ultimately ending — our use of privately operated prisons," Deputy Attorney General Sally Q. Yates wrote in the DOJ memo.

Private prisons have come under heavy criticism in recent years, thanks to scathing reports like one by HBO's John Oliver back in 2014 and an in-depth investigative piece by Mother Jones this June that detailed the harsh conditions and major problems at a for-profit prison in Louisiana.

Is the Justice Department's announcement the beginning of the end for the private prison boom in America? The stock market seems to think so. The world's two largest private prison companies, Corrections Corporation of America (CCA) and GEO Group Inc., saw their stock prices plummet 35 and 40 percent, respectively, after the announcement.

But Alex Friedmann, managing editor of Prison Legal News and head of watchdog group Private Corrections Institute, doesn't seem to think the announcement will make much difference.

"It will have little immediate impact on the U.S. prison system as a whole," said Friedmann, noting that the change has no effect on state prisons, local jails or immigration detention facilities. "The phaseout of privately-operated facilities that house federal prisoners will take five years, and a lot of things can happen during that time period, starting with who is in the White House following the November elections."

Friedmann is an outspoken advocate for private prison reform after spending six years in one of CCA's correctional facilities. After his release in 1999, he became a small shareholder in CCA and has used that investment to take aim at the private prison system — particularly for its treatment of prisoners.

In fact, the Justice Department released its own scathing report a week prior to Yates' announcement and found the treatment of prisoners at private facilities to be troubling.

"In most key areas, contract prisons incurred more safety and security incidents per capita than comparable [Bureau of Prisons] institutions and that the BOP needs to improve how it monitors contract prisons in several areas," the report stated.

The DOJ report highlighted one case in 2012 when a prison riot in Mississippi resulted in 20 injuries and the death of one correctional officer. The inmates "were angry about low-quality food and medical care, as well as about correctional officers the inmates believed were disrespectful."

Leonard Sipes, who retired in June after more than 25 years in the criminal justice system, blames this on the lax hiring practices by private prisons.

"Prisons are run by inmates, not correctional staff. Informal, unwritten compacts among inmates have more meaning for the safety and security of the institution," said Sipes, who now runs Crime in America.Net. "It takes trained, veteran professionals to figure this out and to apply formal sanctions within the framework of informal control. Contract prisons do not attract the same caliber of professionals as do state and federal institutions."

Sipes said officers at government-run facilities receive better training and are more committed to long-term careers in corrections. This professional investment leads to better outcomes for both the prisoners and the officers.

"Inmates want firm but fair application of rules," he said. "They don't get this from private prisons."

So will this change on the federal level influence state governments to follow suit? Friedmann and Sipes are both skeptical.

"States don't have the budget capacity to do away with private prisons," Sipes said.

"It's hard to say whether the decision to do away with privatized federal prisons will trickle down to the state level, as they are different 'markets,'" Friedmann said. "Regardless, a number of states have independently decided to stop using private prisons, including Kentucky and Idaho."

Idaho officials made their decision after a lawsuit and an FBI investigation into an understaffed CCA facility that was so violent that inmates dubbed it "Gladiator School," according to The Associated Press.

Nevertheless, the Justice Department's move is a big step in the right direction for private prison reform advocates like Friedmann.

"The growing trend appears to be against for-profit prisons," Friedmann said.