Will Campos in 2014 at the opening of the Langley Park Multi-Service Center. (Marvin Joseph/The Washington Post)

William A. Campos, a former Maryland state delegate and former Prince George’s County Council member, has pleaded guilty to accepting about $40,000 to $50,000 in bribes and kickbacks in exchange for official favors, federal prosecutors announced Tuesday.

The bulk of the illegal activity involves Campos’s directing more than $325,000 in government grants or funds intended for charitable giving to business owners, nonprofit organizations and other parties in exchange for personal payments while serving on the Prince George’s council.

Campos, 42, a Democrat from Hyattsville, pleaded guilty to bribery and conspiracy Jan. 5, and the plea was unsealed Tuesday.

“Mr. Campos’s favorite charity was himself,” U.S. Attorney Rod J. Rosenstein said after the plea was announced. “He treated the taxpayers’ money as if it were a literal slush fund.”

Campos admitted to accepting payoffs on at least eight occasions between 2007 and 2014, according to the plea agreement, and encouraged some bribers to set up sham nonprofit entities to make it easier for him to funnel money to his benefactors.

The government unveiled the case against Campos less than a week after federal prosecutors charged four others in a pay-to-play investigation. The wide-ranging investigation alleges corruption among politicians and business owners, including accusations that store owners and a county liquor board official bribed elected officials in return for favorable votes on proposals that would expand alcohol sales in Prince George’s.

Public disclosure of Campos’s plea and the related liquor board probe cast a cloud over the run-up to Wednesday’s opening of the state legislative session, as Rosenstein said “more than one legislator remains under investigation.”

[30 months of wiretaps, hundreds of recordings underpin Md. bribery charges, prosecutors say]

Campos admitted taking bribes and kickbacks as early as 2007 — his first term on the County Council — and through 2014, according to his plea agreement. Campos engaged in three major types of corruption: funneling county government grants to business owners in exchange for payments; accepting kickbacks for steering county money to some individuals’ charities; and writing a letter of recommendation on county letterhead in return for $2,000.

In December 2012, the plea agreement shows, Campos accepted an envelope stuffed with $3,000 in the bathroom of a College Park restaurant after discussions with an FBI informant and another individual about helping to move the informant’s business to the county. After picking up the cash, Campos promised to direct $10,000 from a county grant program to a nonprofit organization the informant could control.

The plea agreement also states that Campos took money to testify before the liquor board on behalf of a nightclub owner and help another business owner with a zoning matter and that he sought money to help pay off campaign-related expenses.

In a brief interview last week, Campos denied knowing anything about the federal investigation. On Tuesday, attorney Barry Wm. Levine issued a written statement on Campos’s behalf in which he described his client as a compassionate, decent and religious man.

“He is deeply remorseful and accepts full responsibility for his profound error,” Levine’s statement said. “People are complex. It would be a mistake to judge him only through the acts which are the subject of his error.”

Council member Deni Taveras (D-Adelphi), who succeeded Campos in District 2, said citizens “are highly disappointed in the actions of Mr. Campos. As an elected official, the residents trusted and looked up to him, and his breach of the public trust is unacceptable and painful.”

Second-term County Executive Rushern L. Baker III (D), who campaigned on battling a culture of corruption that marked the administration of his predecessor, Jack B. Johnson (D), said, “It’s disappointing people haven’t gotten the message that those days in Prince George’s County are over.”

Johnson, who served as county executive from 2002 to 2010, pleaded guilty to extortion and witness and evidence tampering after masterminding a corruption conspiracy in which prosecutors said he received more than $1.6 million in bribes.

Campos must give up the money he collected in the scheme and pay restitution of at least $340,000 as part of his plea agreement. Campos also faces up 15 years in prison for the bribery and conspiracy charges. His sentencing is scheduled for April 10.

In a statement sent to friends and supporters, Campos said that the investigation had been going on for years and that he immediately admitted wrongdoing when approached by the government.He said he was “relieved” the “torturous” process was coming to an end.

“As embarrassing and devastating as this may be, I own up to my mistakes,” his statement said.

Campos also alluded to the wide reach of the investigation, saying, “I know what lies ahead for many others,” and asking for prayers for them.

Last week, two government officials and two business owners were arrested in a related case: David Dae Sok Son, 40, the director of the liquor board in Prince George’s; Anuj Sud, 39, a county liquor board commissioner who resigned on Friday; Young Jung Paig, 62, owner of Central Avenue Restaurant & Liquor Store; and Shin Ja Lee, 55, owner of Palmer Liquor Store.

[Federal bribery charges filed over Prince George’s County liquor licenses]

Federal prosecutors say the cases are related but would not detail how Campos was involved with the liquor-board probe. In a charging affidavit released last week, prosecutors said that two elected officials began cooperating with the liquor board investigation in exchange for a more lenient sentence on other corruption charges.

One of those cooperators was identified as a former elected official who took a plea agreement and helped federal agents in the case between June 2014 and July 2015, which would be just months before Campos resigned from the state legislature. Prosecutors do not identify their informants and would not say whether Campos is the former elected official they described as having taken a plea deal.

Campos’s plea agreement includes several details — including conversations, cash amounts, promised favors, locations and dates — that appear to align with the charges filed last week.

Senate President Thomas V. Mike Miller Jr., a Democrat whose district includes part of Prince George’s, said he discussed the bribery allegations with Gov. Larry Hogan (R) on Friday, and emphasized the need to appoint reputable, civic-minded commissioners to the liquor board.

“Everyone’s concerned about it. You should be concerned if it’s happening in Tennessee or Ohio, and it’s happening here in Maryland,” Miller said Tuesday.

The Board of License Commissioners is a state entity that regulates the sale of alcohol in the county at more than 600 liquor stores, restaurants and other businesses. The board’s five commissioners are appointed by the governor to three-year terms.

[Latino state lawmaker from Prince George’s resigns 9 months into job]

Campos became Prince George’s first Hispanic county council member in 2004, winning a special election to fill a vacant seat. He was reelected twice and served 10 years before becoming a state delegate in 2014.

Campos, considered an up-and-comer in county politics, stepped down from the state legislature nine months into his tenure, saying he wanted to focus on his new marriage, starting a family and his career.

While Campos served as a county council member, prosecutors said, Prince George’s officials allowed each member to award $100,000 in grants and funds to nonprofit service organizations of their choosing.

In recent years, council members have opted to have the Community Foundation of Prince George’s, a subset of the Community Foundation for the National Capital Region, manage the discretionary funds — now totaling $107,000 per council member — on their behalf instead of having legislators disburse the funds directly.

County Council Chairman Derrick L. Davis, who served on the council with Campos, said that the allegations against his former colleague are a “serious matter” and that the body is “taking a look” at the system for distributing grants and discretionary funds.

Rosenstein said Campos was “cavalier” in his dealings and “confident” no one would catch him. But Campos explained his actions differently when picking up a $2,000 bribe in the parking lot of an Alexandria restaurant.

“I’m a mortal man,” Campos said, according to the plea agreement. “That’s the problem.”

Fenit Nirappil, Cheryl W. Thompson and Ovetta Wiggins contributed to this report.