Two small children were found unattended in an apartment here recently, one of them bearing the marks of old and fresh beatings. Neighbors told police the children were habutually left unattended by their mother, a drug addict.

In another case, a 14-year-old with a history of running away came home in the predawn hours and said she had been raped. The girl's guardian locked her out of the house.

These two and more than 800 other cases of child abuse and neglect were reported to the Metropolitan Police Department's youth division in the past year. Nearly half the children were physically abused and three of them died.

Child abuse and neglect is recognized as a widespread, but unmeasured problem, that transcends geographic, economic, educational and racial lines.

The District of Columbia this autumn will join a growing minority of states with modern statutes designed to detect, prevent and correct the problem. But city officials say they are ill prepared to handle even the cases that currently come to the attention of police and the D.C. Department of Human Resources.

Five years ago District children victimized by neglect, abandonment, abuse, eviction, poverty on parental illness and death were place in Junior Village, a sprawling institution in far Southwest.

Reports of truancy, sexual assault, separation of siblings, theft rings and general lawlessness among children at the facility moved the City Council in 1971 order it phased out over a two-year period.

DHR shut down Junior Village by the Council mandated deadline of September 1973, but failed to develop enough alternatives, such as foster care and group homes, for its neglected and abused dependents.

Consequently, healthy children were placed in hospitals, where some of them contracted disease, contracts were led and later canceled with fly-by-night group home operators, and some city wards reportedly wandered the streets following the facility's closure.

A law-suit filed by For Love of Children an organization that operates several reputable children's homes, led to a consent decree last year requiring quarterly DHB reports on the placements of all neglected children in its custody. The most recent report filed last April, showed 2,156 placements, and DHR officials say they now have enough homes.

But DHR officials and private groups concerned with children say DHR's handling of city wards still has serious shortcomings.

With only 43 of its 89 positions currently filled, the DHR protective service unit, charged with counseling and monitoring troubled families, and placing children found in unsafe homes, has a case load far above nationally accepted standards.

"Family services (the DHR bureau that enfolds protective services) can only do crisis and demand work" because of the staff shortage, bureau chief Betty Queen said recently. "We're concerned about the front end" work to prevent family crises that necessitate removing children from their families, she said.

A recent exemption to the city's personnel ceiling opened recruitment for 25 more protective service employees, but Helen Dean, the division chief said she needs an additional 20 workers just to handle present work loads.

Moreover, the legislation passed by the City Council last month enlarging a list of professional people coming into contact with children who will now be required to report suspected maltreatment could multiply incidents requiring investigation by 600 per cent, according to Dean.

The comparative trickle of reports that police and DHR now receive usually come from relatives or neighbors of the families involved. Most calls are anonymous and two-thirds of them prove to be well-founded, according to police youth division chief Sgt. Robert Seguin.

In one unusual case last week, protective service worker Tony Pickens found merit in a report from an 11-year-old girl. Pickens, one of only six workers assigned to the unit's 24-hour emergency section, found the child and a younger brother alone in the home at 10 p.m.

The child explained that she had asked the telephone operator for "adoption" and reached DHR after several referrals. The child said her mother often left the children at home alone all day and without food and "hits me for nothing."

Pickens removed the children to a neighbor's house and left a note to the mother, who was later warned that she could face legal action if the situation continued. Only the police are authorized to take children into custody without a court order or parental consent.

While authorities express concern over how to cope with the expected increase in reported incidents ehen the new law takes effect, they also worry, Seguin and Pueen said, about cases that now go unreported.

Seguin said police are trying to find out why most of the District's private hospitals never report suspected abuse, although the department is confident that they see evidence of it.

Of the 386 battering cases investigated by police last year, nearly all reported by hospitals came from D.C. General. Children's and Howard University hospitals, Seguin said.

Queen, referring to the death last month of an 8-month-old who was left alone in an abandoned building by his 17-year-old mother, blammed the child's death on "someone's failure to report the neglect.

Like the dead baby's mother, who was from rural Virginia, many of the protective service cases are families who are destitute, according to Donald Butler, supervisor of the 24-hour workers.

"People are coming to Washington (in larger numbers) to try make it, with no plan - nowhere to stay." Butler said "They just show up." The unit is obligated to investigate and aid any legitimate case of homelessness, however, he said.

In addition the heavy case loads they maintain, protective service workers are set apart from other social workers by the sometimes dangerous nature of their responsibility, according to Dean.

"We're dealing with parents who have alcoholism and drug addiction problems, and they're misfits for city living," Dean said. Workers have had their lives threatened, she said.

"The removal of a child from an addict may mean removal of an AFDC (welfare) check," Dean said. "They fight hard in court to keep their children, even though they'll leave them unattended."

Under the city's new child abuse law, persons reportingsuspected incidents will have immunity from prosecution or civil suits, while anyone found guilty of deliberately failing to report could be fined $100 or imprisoned for 30 days.

The law also strengthens the city's ability to terminate parental rights, thus shortening a child's stay in foster care by facilitating adoption. In addition, it mandates that DHR establish a central register of information on abuse cases.

Nurses, doctors, school officials, social workers, day care workers and mental health professionals are among those the law requires to report any suspected neglect or abuse.

The bill will take effect 30 congressional legislative days from July 6, when the mayor signed it.