Charles W. Rinker Jr., a Methodist minister who worked for Youth Pride, Inc. and its related business for nine years, said yesterday that he is innocent of the criminal charges placed against him Monday. But Rinker also said that he now believes "there was some money taken, but I'm not sure who was responsible."

Rinker said he was "flabbergasted" to have been among five persons indicted for stealing and misappropriating thousands of dollars from three low-income housing projects managed by a real estate spinoff of Youth Pride. "I really think the U.S. Attorney's Office did not have any sufficient reasons to indict me for anything," Rinker said.

Rinker said he does not believe there was any conspiracy to defraud the government, as prosecutors allege, but that some people may have taken money at times when "the opportunity was there."

A federal grand jury charged in a 30-count indictment that Rinker, three other officials of the spinoff, P.I. Properties, and an accountant, portrayed P.I. Properties as a charitable, nonprofit business, but actually used it illegally to fund their own profit-making enterprises and to pay personal expenses.

Mary Treadwell, former director of P.I. Properties, general manager Robert E. Lee, resident manager Joan M. Booth and accountant Ronald S. Williams were indicted along with Rinker for conspiracy to defraud the government, making false statements to federal agencies, mail fraud and wire fraud.

Arraignment for the five has been set for March 3 at 9:30 a.m. before U.S. District Court Judge John Garrett Penn.

Treadwell refused yesterday to discuss the matter with a reporter from The Washington Post. She told an interviewer from WJLA-TV (7) that she was the victim of an investigation motivated by political concerns.

She said The Washington Post, which first reported the P.I. Properties operations that were the subject of the indictment handed up Monday, started a 14-month investigation of the firm during the 1978 Democratic primary when her ex-husband and fellow Youth Pride founder, Marion Barry, was running for mayor. "I don't think that was a coincidence," she said.

Treadwell told an interviewer from WRC-TV (4) on Monday that she "did not steal anything" from Clifton Terrace or from P.I. Properties and that she was "glad that this has reached the level where I will be able to answer back, and there will be the kind of opportunity to put my side out."

Noting a statement Monday by Stanley S. Harris, the U.S. attorney for the District of Columbia, that the federal investigation would continue, Treadwell said she thinks the future probe would not deal with Youth Pride or with Clifton Terrace, the 285-unit apartment building run by P.I. Properties and the focal point of Monday's indictment. "I think it's going to be more than interesting to watch," she said.

None of the charges have implicated Barry, who was never an official of P.I. Properties, divorced Treadwell in 1977 and has said that he severed all ties with Youth Pride and its related organizations in 1978.

Lee, Booth and Williams have not been available for comment since the indictments were handed up.

Rinker, a former secretary-treasurer of P.I. Properties, was charged along with the other four defendants with making false statements to the government--particularly some monthly financial reports to the Department of Housing and Urban Development--and with authorizing company bank transactions that wound up being used for personal expenses of other alleged conspirators.

In a lengthy telephone interview from his home in Arlington yesterday, Rinker said he did not provide any information to the government that he knew to be false, nor did he authorize any money to be used for other than what he thought to be legitimate company purposes.

In addition, he said, most of the charges dealt with alleged events after mid-1976, when, he said, he ceased to be involved with P.I. Properties.

All his work for P.I. Properties and the other Youth Pride-related businesses, he said, was motivated by a basic egalitarian desire to work for "a better society, more equal, and a more just economic order."

Rinker was an officer, director or employee of five of Treadwell's spinoff businesses as well as Youth Pride and P.I. Properties. He said he saw no reason to suspect anything amiss. "Maybe I was naive. I basically trusted people," he said.

A native of Winchester, Va., Rinker became an ordained minister after completing seminary school in New Jersey, and migrated to Washington to become involved in the civil rights struggles of the 1960s. "This is where I thought I could be helpful, my call, if you will," he said.

He met Marion Barry while crusading against slum housing, he said, and later Mary Treadwell, and began working for both of them at Youth Pride in 1969. He then took on posts with other Pride spinoffs to work for improved housing and economic development for minorities, he said.

Of Treadwell, he said: "I always felt her commitment for housing and training was there."

He left Youth Pride and the Treadwell businesses in April 1978, Rinker said, because "I just basically felt that the businesses weren't going to be successful and the dreams I had worked so hard for weren't going to come to fruition."

Since then he has worked for ACTION, the federal volunteer services agency, and in recent years has headed his own consulting company to help low- and moderate-income tenants get home financing and home improvement loans.

Rinker, 41, ran unsuccessfully for the Arlington County board in 1979 and is currently chairman of Virginia's 10th District Democratic Committee. A resident of Arlington's Ashton Heights neighborhood since 1969, he is active in other civic endeavors, is married and has three children.

Rinker said he met with prosecutors twice and cooperated fully with them. He was informed he was a target of the grand jury investigation last November, he said, but even so, he never thought he would actually be indicted.