Clarification dated December 19, 2016: In connection with reporting regarding the pornographic emails that were sent on state computers, the article below suggested that Marc Costanzo had sent pornographic emails while he worked at the Attorney General's Office. For clarification, according to interviews and documents now available to the Daily News, Mr. Costanzo did not send any pornographic or otherwise inappropriate emails while at the agency.

DISTRICT Attorney Seth Williams practically begged state Rep. Louise Williams Bishop to take a sweetheart deal: She could plead guilty to bribery charges in return for probation and keep her state pension, according to Bishop's defense attorney.

"I told him to go pound salt - kiss my ass," said the attorney, A. Charles Peruto Jr., recounting a conversation in Williams' office in early 2015. "It was a sit-down with me and my client, and he begged us to take a deal."

The case "stunk to high heaven," Peruto told the Daily News last week.

Peruto soon would learn of accusations that top prosecutors on Bishop's case had instructed the lead investigator to "target" black politicians, even though a confidential informant, Tyron Ali, initially had pointed them in the direction of at least four white state lawmakers, according to a May 2013 memo written by First Deputy Bruce Beemer to his new boss, Attorney General Kathleen Kane.

This summer, Peruto, along with the rest of the public, learned that Frank Fina and Marc Costanzo - the top prosecutors on Bishop's case - had sent and received racist and pornographic emails while simultaneously building their case against Bishop and other black legislators. At the time, they worked for the Attorney General's Office.

Now it appears that the racist emails could affect the pending criminal cases against Bishop and state Rep. Vanessa Lowery Brown.

Kane dropped Bishop's case, declaring it "not prosecutable." Fina and Costanzo left Kane's office and went to work for Seth Williams. Fina and Costanzo handed Williams the case and he ran with it. In March 2015, Williams heaped felony bribery-related charges on Bishop, 82, a beloved fixture on radio stations WHAT and WDAS. He also brought charges against then-state Reps. Michelle Brownlee and Ron Waters, state Rep. Brown and former state Rep. Harold James.

Bishop and the other legislators, all black and all from Philadelphia, were caught on tape accepting money or gifts from lobbyist-turned-informant Ali. Bishop is accused of accepting three cash payments totaling $1,500.

Brownlee, Waters and James all pleaded guilty in June to corruption charges for accepting cash payments from Ali and were sentenced to probation: 18 months for Brownlee, 23 months for Waters and a year for James.

During a news conference in March, Williams lambasted Kane for failing to prosecute corrupt politicians and for accusing him of "harboring racists in my office." It was an "I-told-you-so" moment for Williams.

Yesterday, Kane appeared to have her own "so-there" moment. When asked by the Daily News if Kane knew about the emails when she dropped the case against the black politicians, her spokesman, Chuck Ardo, wrote in an email: "What the Attorney General knew was that there were allegations of racial targeting made against one of the central figures in the Porngate scandal. The consequent discovery of the offensive email material made those allegations more plausible."

Peruto said he believes that the emails further bolster his argument that a judge should dismiss the charges against Bishop because his client is a victim of racial targeting, or "selective prosecution." Peruto is pushing for the emails to be made admissible in court.

"I am not going to back down on behalf of Bishop," Peruto said. "Everything is going to be exposed . . . I believe there is going to come a day when Seth Williams wishes that he had left this alone. He is going to be very sorry that he stuck his nose in this."

Civil-rights and black leaders have called for Williams to fire Fina, Costanzo and a third prosecutor, Pat Blessington, at the center of the Porngate email scandal. Yesterday, Williams put out a statement detailing sensitivity training that staffers participated in on Friday.

"As it relates to Frank Fina, Marc Costanzo and Patrick Blessington, I know that they found this training seminar as instructional and helpful as I did," Williams said, adding that the three men "are great prosecutors who clearly made a big mistake."

Williams' office declined to answer questions yesterday from the Daily News about whether the emails were a concern against the backdrop of the pending criminal trials of Bishop and Brown.

The Daily News also asked, in an email sent to Williams' spokesman Cameron Kline, why Williams would offer such plea deals to lawmakers accused of taking money and bribes while in office. Kline said he could not answer the questions "because it is still an active case."

Internal memos from the attorney general's file on the case, which Fina once had dubbed the "Black Caucus" investigation, show that Ali made 113 recordings. Of those recordings, 108 - or 95.5 percent - target blacks.

In the May 21, 2013, memo, Beemer advised Kane to drop any criminal case against Bishop and four other black state legislators, although he laments that choice.

"[T]here is significant evidence of certain legislators engaging in illegal and unethical practices," Beemer wrote. "This information, however, pales in comparison to the problems that exist in this case."

One problem, noted Beemer, is that top prosecutors seemingly pushed to "focus only on members of the Legislative Black Caucus," which Beemer described as "shocking" and potentially crippling to an effective prosecution.

Perhaps the biggest problem, Beemer asserted, is the "unjust" plea deal granted by Fina to Ali.

A grand jury had indicted Ali on charges that he stole roughly $431,840 from 2004 to 2007 in taxpayer money earmarked to provide low-income children and senior citizens with nutritious meals. Ali used the money for personal gain, including traveling, dining, clothing, jewelry, car payments and insurance payments. In all, the grand jury slapped him with 2,088 criminal counts in 2009.

Ali wanted to cut a deal and said he had information about a "hotbed of fraud, theft and misappropriation" of grant money, totaling millions of dollars, by white and black state legislators. Fina agreed to drop all 2,088 charges filed against Ali in exchange for his continued cooperation, documents show.

Peruto said Fina and other state prosecutors had a "monumental" fraud case against Ali. In the end, "Ali laughed all the way to the bank," Peruto said.

Peruto said that Williams played the recordings that Ali made of Bishop when he begged her to take a plea.

"I said, 'If that's the best you got, you people are nuts,' " Peruto said.

Peruto has had his own problems with Williams. It was Williams who opened a grand-jury investigation into the death of a young woman found in the bathtub of Peruto's Rittenhouse Square townhouse. Peruto wasn't home at the time. After months of investigating, Williams' office concluded that the death was accidental, the result of alcohol poisoning, and found "no evidence of criminality." Peruto has said he had to endure the loss of his "soulmate," while dealing with a cloud cast over his reputation by Williams.

On Twitter: @wendyruderman