Philadelphia prosecutors announced criminal charges Tuesday against two more elected officials swept up in the undercover sting investigation that state Attorney General Kathleen G. Kane had argued could not be successfully prosecuted.

District Attorney Seth Williams announced conspiracy, bribery and conflict of interest charges against state Reps. Vanessa Lowery Brown and Ronald G. Waters, both Philadelphia Democrats, for accepting cash from an undercover operative.

In announcing the charges, Williams had harsh words for Kane, who he said had to be forced through "judicial intervention" to turn over key documents in the case.

As for Kane's assertions that the sting investigation, begun by her predecessors, racially targeted elected officials, Williams said they were false, and that he was "disgusted" by them.

"It's pouring gasoline on the fire for no reason, no reason at all," said Williams.

The charges are the result of an ongoing grand-jury investigation.

According to sources, Waters is currently exploring a deal with prosecutors under which he would plead guilty to the felony charge of conflict of interest, but a bribery charge would be dropped.

While such a conviction would require Waters to step down from office, it would protect him from the loss of his state pension. A bribery conviction would cost him his pension.

It was unclear whether any negotiated plea would call for him to serve time behind bars.

Williams' announcement brings to three the number of Philadelphia Democrats implicated in the sting to face charges. Two others - state Reps. Louise Williams Bishop and Michelle Brownlee - remain under the grand jury's scrutiny.

The Inquirer has reported that Waters pocketed the most money from the undercover operative of any of the five politicians caught up in the sting: $8,250 in eight payments. Brown has been described as having received the second most: $5,000, in six payments.

In interviews before The Inquirer revealed the aborted sting on March 16, Brown declined to discuss the matter. Through her lawyer, she had denied any wrongdoing.

Waters, for his part, said he may have received something from Ali on his birthday.

Investigative documents reviewed by sources familiar with the matter say Ali gave Waters $1,000 in April 2011 to mark the veteran legislator's 61st birthday. The transaction was captured on tape, according to people who have read a transcript of the conversation.

As Ali handed Waters an envelope, the sources said, Ali told him: "Hey, there's $1,000 in there, bro."

Waters replied: "My man, happy birthday to Ron Waters."

The documents also say that in May 2011, Ali went to Brown's office and handed her an envelope containing $2,000.

According to people who have reviewed transcripts of the tape, as Brown accepted the money, she put it in her purse and said: "Yo, good looking and ooh whee . . . Thank you twice."

The plan to charge Waters and Brown will mark another professionally embarrassing moment for state Attorney General Kane, who earlier this year dared Williams, a fellow Democrat, to take on a case that she at one point characterized as "dead on arrival."

Kane could not be reached for immediate comment.

Kane shuttered the sting in 2013, without bringing any charges and without informing the state Ethics Commission that the investigation had allegedly caught the four legislators, as well as a former city Traffic Court judge, Thomasine Tynes, on tape accepting cash or gifts.

The details of the case were buried in sealed court files.

After The Inquirer first broke the news of the aborted operation, Kane vigorously defended her decision. She contended the investigation was poorly managed, relied on a questionable undercover agent, and was possibly tainted by racial targeting. All five elected officials captured on tape are African American.

Kane said that the lead agent in the case had told her office that he was directed to pursue members of the Legislative Black Caucus - an assertion the agent, Claude Thomas, vehemently denied. Thomas now works for Williams.

The sting was launched in 2010, when Republican Gov. Tom Corbett was attorney general. The investigation was led by Frank G. Fina, a top prosecutor in the office who left after Kane was elected in 2012. Fina now works for Williams in the office's public corruption unit.

The undercover operative in the probe, Philadelphia lobbyist Tyron B. Ali, offered money and gifts to elected officials, often as he sought to influence their vote or land government contracts.

Williams last month announced charges against Tynes, the former judge. In a negotiation with the District Attorney's office, Tynes has agreed to plead guilty to conflict of interest for accepting a $2,000 Tiffany's silver bracelet from Ali as he was seeking a contract with the Traffic Court.

Tynes, 71, is scheduled to enter that plea Wednesday. As part of her deal, city prosecutors agreed not to seek any more prison time for her on top of the two-year sentence she recently received for a perjury conviction in an unrelated federal case involving fixed traffic tickets.

The Inquirer has reported that Bishop, 81, accepted a total of $1,500 during three meetings with Ali, and that Brownlee, 58, accepted $2,000 wrapped in a napkin from Ali in 2011.

In past interviews, Bishop said she had not accepted money from Ali and did not know him. Brownlee said she could not recall accepting such a payment.

As Ali plied the legislators with money orders or envelopes stuffed with cash, he often would ask them for an official favor.

For instance, Ali sought support from Waters in late 2010 for a bill that aimed to privatize the state wine and liquor stores. Telling the legislator he needed to exercise his "God-given right of leverage," Ali handed Waters an envelope with $500, according to the investigative documents.

Ali became an undercover agent for the Attorney General's Office after facing legal problems of his own. He was charged by state prosecutors in 2009 with defrauding a state food program for low-income children and seniors out of $430,000.

In exchange for his cooperation, prosecutors agreed to drop the charges.