Indicted Ald. Willie Cochran (20th) on Thursday blasted the federal case against him as the former City Council sleuth who brought it to the feds warned of “a handful” of aldermanic indictments to come.

Cochran unleashed his anger — and former Legislative Inspector General Faisal Khan took a bow — one day after a 15-count indictment accused the South Side alderman of looting a 20th Ward fund meant to help children and senior citizens, using $5,000 to pay his daughter’s college tuition and withdrawing $25,000 from ATMs near his preferred casinos.

The former Chicago Police officer was also accused of accepting bribes from local businessmen seeking favors, including the sweeping power that aldermen still wield over liquor licenses and zoning matters.

In a bizarre scene, even by Chicago’s sordid standards, Cochran attended a City Council meeting on the day of his indictment. He sat through an hour-long tribute to the World champion Cubs as word spread like wildfire of the corruption charges against him.

On Thursday, the embattled alderman responded to a series of text messages from the Chicago Sun-Times.

One message came in response to a question about allegations that he shook down a liquor store owner and stole tens of thousands of dollars in charitable contributions meant for kids and seniors.

“I have never extorted money. That will be revealed. I am a giver — not a taker,” Cochran wrote.

“My emphasis has been and will continue to be on seniors and youth.”

In another exchange, Cochran was asked why he withdrew $25,000 from automatic-teller machines in or near casinos where he gambled.

He replied, “Account been closed 3 years. Do the math: $25,000 [divided by] 5 yrs. (2009-13)=$5,000. $5,000 [divided by] 12 months=$416-a-month. Less than 9% admin fee. Is that worthy of a charge in an indictment?”

Cochran was also asked: why his charity wasn’t registered; why his aldermanic salary and police pension were not compensation enough; whether he had a gambling problem and what he had to say to 20th Ward residents who have seen two of Cochran’s predecessors go to prison and trusted him to honor his promise to be different.

All of those questions were ignored.

The case against Cochran was built by Khan in what he called a “lengthy” investigation launched in 2013.

It was based on a signed and sworn complaint and subpoenaed testimony that complied with rules imposed on the Council’s handpicked inspector general — rules that were tailor-made to tie Khan’s hands.

That’s what made the Cochran indictment — along with U.S. Attorney Zachary Fardon’s attaboy to Khan — so rewarding to Khan, whose office was abolished a year ago.

Not only had Khan hit paydirt, despite the obstacles and insults thrown his way by aldermen who hired him in the mistaken belief that he would become their political patsy.

It could be the first of a “handful” of aldermanic indictments triggered by the cases he developed and turned over to the feds.

“Mr. Cochran was not the only one engaging in this type of behavior, this illegality. A number of aldermen engaged in conduct that is criminal. We’ll probably have this conversation again in a few months,” Khan said, without naming names.

“We referred a number of investigations to the FBI, including this one. Once they complete the remainder of the work we began, I hope there will be some fruition from our work, including appropriate charges.”

Khan said he views the latest charges as an indictment of “Chicago and its culture of corruption.”

He said the only cure for that chronic political illness is to overhaul Chicago’s “archaic” ethics ordinance, blow up an “ineffective” and revamped Board of Ethics and empower Inspector General Joe Ferguson to audit City Council programs exempt from his purview.

“Take away confidentiality. Taxpayers need to know who the inspector general is investigating and why. Take away the ability for the Board of Ethics to protect opinions given to elected officials. Make penalties far greater for misconduct. Stop allowing the Board to be lawyers for aldermen, instead of taxpayers. Make financial disclosure and conflict of interest statements far stronger,” he said.

In New York City, elected officials must provide “literally a book of information,” including bank account statements and numbers and credit card numbers, Khan said.

“We need to look at those and see if an elected official is susceptible to a bribe or theft or is in a position where they may need money to solve problems like Mr. Cochran’s gambling issues,” he said.

He added: “For years, we’ve listened to a mayor talk about fixing the ethics problems in Chicago and claiming he’s done so through superficial ethics changes. But the reality is that things are worse-not better.”

The Chicago Sun-Times reported earlier this year that Khan was paid nearly $800,000 over his four-year term for what was supposed to be part-time work. He also sued the city for tens of thousands of dollars he claimed to be owed.

Khan has maintained that his salary was “the same as any other” city department head minus the sick days, health insurance and pension benefits offered to full-time city employees.

Basking in the glow of Cochran’s indictment, Khan apologized to no one.

“I was dealing with a City Council that belittled us on every move, blocked us at every turn and insulted us at every opportunity, knowing full well we would not respond publicly because they wrote the law making sure we couldn’t,” he said.

“Despite all of that, we were able to accomplish what we accomplished: this indictment of Ald. Cochran. Inspector Clouseau got his man. And there’s more to come.”