The district attorneys for Multnomah, Washington and Clackamas counties announced Tuesday that they will drastically cut back prosecutions of people who evade paying TriMet fares.

The prosecutors said the move is in response to a Portland State University study in December and their own research that found African American riders caught riding MAX trains without paying faced bans from TriMet at a noticeably higher rate than white riders.

Fare evaders who are criminally prosecuted have frequently been charged with interfering with public transportation, which is classified as a misdemeanor under state law. Prosecutors say they plan to stop pursuing criminal charges against hundreds of fare evaders caught annually -- except in extreme cases or cases of chronic offenders.

They don't want the public to take this as a sign that they're going easy on evaders, the prosecutors said, and stressed that people who don't pay to ride will still face consequences.

Fare evaders could be ticketed and fined administratively by TriMet, they said. Riders who threaten or assault operators or other passengers will still face criminal charges in state court.

"All people who ride TriMet need to feel safe," said Rod Underhill, Multnomah County's district attorney.

Prosecutors call for new fare evasion policy 3 Gallery: Prosecutors call for new fare evasion policy

On top of concerns about the racial disparity, prosecutors said the policy change also was prompted by concerns that prosecuting fare cheats in the criminal justice system is too heavy-handed. Fare evaders can be handcuffed, arrested and brought to jail even though -- at least in Multnomah County -- they often see their cases downgraded to violations, similar to a traffic ticket.

"It is of the highest importance that justice guides our prosecutorial decision," said a joint statement from Underhill, Washington County District Attorney Bob Hermann and Clackamas County District Attorney John Foote.

Hermann told The Oregonian/OregonLive that poverty may be a motivating factor for some fare evaders.

"That's a reality: There are people who may need to get from one place to another and they don't have a money," he said.

Defense attorneys cheered the change.

"I've already sent them a congratulatory email," said Lane Borg, executive director of Metropolitan Public Defender Services. "It's a great thing that they've done this. ... We need to call out racism in the system."

Borg said he also agreed that the charge of interfering with public transportation didn't fit the act of fare evasion. Those who have been prosecuted repeatedly find themselves in a hole of fines and court obligations that keeps getting deeper -- and often is difficult to escape, he said.

The three district attorneys said they were examining the issue of fare evaders just as PSU's Criminal Justice Policy Research Institute released its study Dec. 14. The study was commissioned by TriMet, which had concerns about racial disparities and approached the district attorneys.

In a statement Tuesday, TriMet said the policy change is "in line with what TriMet believes to be fair." Agency officials said they have been pushing for change that ensures equitable enforcement without being overly punitive.

Up to now, passengers caught without proof of payment on MAX for the first time faced various consequences: a warning, a ticket or an exclusion from TriMet that can last up to 90 days, depending on the discretion of the TriMet fare inspector or police officer making the stop.

Those caught again could face arrest on the interfering charge, also at the discretion of the inspector or officer.

The PSU study found that African American riders were more likely to be banned from riding TriMet when police -- opposed to the TriMet inspectors -- were involved.

The disparate treatment was small but noticeable: A difference of about 152 encounters out of 5,900 exclusions over the past two years made the number statistically significant.

-- Aimee Green