Why would the instigators of a murder-for-hire plot get lighter sentences than the gang members they solicited to commit the crime?

That's the question the San Bernardino County district attorney's office is having trouble answering these days.

Stacy Nunez-Barajas, and her brother, Erik Barajas, members of the San Manuel tribe, pleaded guilty to asking Mexican Mafia members to rub out a man who allegedly robbed Barajas.

But unlike the two men who pled guilty to the attempted murder of Leonard Epps, Barajas and Nunez-Barajas will spend the next five years on probation, including short stints under house arrest.

The would-be hit men, brothers Salvador Orozco Hernandez, 43, of Bloomington, and Alfred Hernandez, 39, of Fontana, are doing up to 10 or nine years respectively in prison.

DA Mike Ramos categorically denies his office cut a favor for the two members of the wealthy San Bernardino tribe, which contributes to his political campaigns and has a $209,000 contract with his office for a tribal-matters prosecutor, investigator and victim-advocate.

"We don't work that way," Ramos told me Friday.

The last thing he would want to do, Ramos said, is to hurt the tribe by not holding members who commit serious crimes accountable.

He didn't know about the plea deals negotiated by lawyers for Barajas and Nunez-Barajas with prosecutor Doug Poston until questions were raised about its leniency, Ramos said.

After learning the reasons behind the deal, Ramos said he supports it.

So what are the reasons?

It had to do with the evidence, Ramos said, including "credibility issues" with Epps. He wouldn't explain, because Epps is the victim of the crime.

Assistant DA for Criminal Operations Dennis Christy was equally circumspect.

"Generally in gang cases, you deal with witnesses and victims that are very, very sensitive from the standpoint (that) there may be issues with them," Christy said.

Issues? Could he be more specific?

"You're dealing with victims and witnesses that are not the most credible," he said.

Wasn't credibility an issue with the Hernandez brothers, who went to prison? Yes, Christy said, but the evidence wasn't equal against all defendants.

Poston told me it takes more than one person to conspire and just because Barajas and Nunez-Barajas initiated the plot doesn't mean they're more culpable than the alleged hit men.

The prosecutors point out that if Nunez-Barajas violates probation, she could spend 21 years in prison. If her brother does, he faces up to eight years.

Epps understandably is upset. His life has been turned upside-down because of a confrontation with Barajas in a Highland bar in 2006. (Barajas says Epps and two others extorted $4,000 from him, prompting him to seek revenge.)

Epps went into hiding on the advice of police. His freedom has been curtailed more than Barajas' and Nunez-Barajas'.

It's too bad the DA can't explain more specifically why the pair deserved probation instead of prison.

If they were being extorted by gang members, they're victims, too. But none of the prosecutors suggested that's why they avoided prison. So "evidence" and "credibility issues" are the generalities the public gets.

Cassie MacDuff can be reached at 909-806-3068 or cmacduff@PE.com