A staff member of the federally financed shelter for the homeless in Anacostia has been arrested on an assault charge after he allegedly struck a homeless resident in the head with a wooden baseball bat, in what police describe as one of several reported assaults on residents by staff.

The accused staff member, Otis M. Bridges, had a long criminal record of which shelter officials were unaware. Police said shelter officials did little or nothing to check the backgrounds of employes, and added that they have received a number of reports that residents of the shelter have been mistreated by staff members.

The Anacostia shelter, which is run by the nonprofit D.C. Coalition for the Homeless, was established last year with a $3.7 million federal grant as an alternative to a downtown shelter run by the Community for Creative Non-Violence that the federal government had called a poorly run, decrepit firetrap and was trying to shut down.

Police arrested Bridges, the shelter's codirector of transportation, on a charge of assault with a dangerous weapon April 2 after an incident three weeks earlier in which resident Spencer Foster lost 70 percent of the sight in his left eye, and suffered fractures of the nose and several facial bones.

Bridges has told police he acted in self-defense. The case was presented to a D.C. grand jury yesterday for possible indictment.

Bridges was hired for his $12,000-a-year job two months after being paroled on convictions of perjury and intimidation of grand jury witnesses. His criminal record also includes convictions in two separate killings: In 1972, he was convicted of second-degree murder and 1976 of involuntary manslaughter. As of yesterday, he was still on the shelter payroll while being held in D.C. Jail on $20,000 bond.

"They didn't check a sole [applicant's] record," said Detective David H. Israel of the D.C. police, who is handling the Bridges case. "They just hired them."

Israel said police are investigating several other reports of residents being assaulted by shelter staff members. "We're investigating reports that they beat them [the residents], take their money, and don't feed them right," he said. "The place is . . . rough."

Elisabeth Huguenin, president of the 5-year-old Coalition for the Homeless, said she was unaware that Bridges had a record.

"It was a very quick procedure," she said of the task of screening and hiring employes. "We put ads in the newspaper. It's difficult to get people because it's a demanding job . . . . I don't think we had time to check in depth."

The U.S. Department of Health and Human Services, in a bitter fight with CCNV spokesman Mitch Snyder to close the downtown shelter run by his group, gave the coalition the $3.7 million grant Sept. 30 to open a temporary alternative shelter as soon as possible and to establish other permanent shelters throughout the city.

Huguenin also said she did not know of any cases of alleged assaults on residents by her 150-member staff. Bridges has not been fired, she said, because he has not been found guilty of the alleged assault and it was her understanding that Bridges acted in self-defense.

Witnesses told police that about 9 a.m. March 11, Christopher Manhold and Spencer Foster, shelter residents who serve as volunteers, were standing next to Manhold's motorcycle in front of the shelter, a former Navy building on 1900 Anacostia Drive.

Manhold was pouring gasoline, which he had collected from a shelter van's leaky gasoline tank, into his empty motorcycle tank, when Bridges walked out of the shelter and demanded that Manhold pay for the gasoline, witnesses told police.

"He demanded money," Manhold said in an interview, repeating what he had said in his statement to police. "I gave him $1 . . . . Three minutes later he demanded more money and I gave him the remaining cents in my pockets . . . . Then he said, 'Who is with this man?' and Spencer [Foster] said he was." Then, Manhold alleged, Bridges struck him with a wooden bat, shattering his sunglasses.

"I had never been in a shelter before, and I'll never go to one again," Foster, 32, said last week from his bed in D.C. General Hospital. A hospital security guard checks his room periodically and accompanies visitors to his room because Foster has reported that his life was threatened in a telephone call.

"I almost lost my life," said Foster.

Efforts to reach Bridges' attorney were unsuccessful. In a statement to the director of the shelter, C.H. Johnson, Bridges said he struck Foster in self-defense and with a "stick" after Foster "waved a knife" at him.

Police said no knife was found at the scene. Several days later, however, police said the executive director of the coalition, Patricia Makin, turned a knife over to them, which she reported that a resident had found on the grounds.

Makin, who is in charge of the staff, said that if there have been problems, "We have been able to handle them ourselves." Asked of reports by residents that donated food and television sets had been stolen by employes, Makin said, "There have never been any thefts."

John F. Kelly, a 71-year-old resident of the shelter, said he was accosted by a staff member in the men's room about two weeks ago. He said a van driver threw him against the wall and took $4 from his pocket. There is no police report on the alleged incident.

Another resident, Gordon H. Jones, said he witnessed the alleged incident and supported Kelly's account.

Anthony Martini, another resident, said he recently had to restrain a security guard who he said was choking a drunken, elderly man. Martini said that when he intervened, another guard pulled him away.

Security at the shelter is handled by a private firm, Diamond Security. Kenneth U. Brown Sr., an owner of the firm, declined to discuss that alleged incident. He said that since his firm has been under contract with the shelter, one guard has been fired for using excessive force.

"People are fleeing Anacostia," said Mitch Snyder, the director of CCNV, which operates the downtown shelter at 425 Second Street NW. "There are lots of reports of excessive violence."

Police said that since Jan. 7 they have received calls to respond to the shelter 72 times, including 13 calls for reported assaults.

Israel, the D.C. detective investigating the shelter, said many of the alleged incidents there apparently went unreported. Even when police did respond, he said, it is hard to prosecute because homeless people often flee if abused, and even if they stay, it is their word in court against a staff member.