Richard Daniels died in the state's care, beaten and bruised, a defenseless victim of repeated neglect that slowly killed him.

Today, 2 1/2 years after his unexplained death at North Dade's Landmark Learning Center for the developmentally disabled, no one has yet been held responsible for abusing him despite evidence that the 43-year-old retarded man, his body bent and paralyzed, may have been beaten to an agonizing death.

A Miami Herald investigation into his death, as well as those of dozens of retarded adults in Florida, shows that the Daniels case, like others, has been hampered by reluctant witnesses, sloppy medical records, poor documentation of crucial evidence and waning interest in his death.

"They didn't even tell me he was dead until three days after it happened," said Barbara Daniels, his mother. "It was such a shock, and no one could ever explain to me how he got all those bruises. My son was abused. There's no doubt in my mind."

A Landmark aide who worked in the cottage where Daniels lived has told The Herald that he saw another employee repeatedly beat Daniels in the chest and stomach in the week before he died and that he once tried to warn his supervisor that Daniels was in danger.

Two months later, Daniels was dead, his case a woeful illustration of a social-welfare system that broke down.

"I'm deeply troubled by what I've seen and heard on this case, and it raises more than a reasonable doubt in my mind about just how he died," said Jim Towey, district administrator for the Department of Health and Rehabilitative Services in Dade, which oversees Landmark. "The Daniels case is just an example of the tragedy that, for me, demands a full accounting from the leadership out there."

In the past five years, dozens of physically and mentally disabled adults have suffered similar fates, the victims of alleged abuse or medical neglect. Many lived in state institutions such as Landmark or in homes sanctioned by the state to care for them.

And yet the state has been hard-pressed to protect them.

Incidents of beatings, mistreatment and blatant violations of a patient's dignity often go unreported despite state abuse statutes because front-line health-care workers fear retribution on the job.

Frustrated welfare investigators, despite repeated reports of abuse and neglect, frequently find it difficult to make a case against anyone when dozens have been responsible for the victim's care.

The Herald found that doctors and nurses in some cases repeatedly fail to order critical medical tests and document life-threatening illness or unexplained injuries. They ignore key medical symptoms, sometimes writing them off to "bad behavior," and then don't act swiftly to send their patients to hospitals for treatment.

Against that backdrop, police and prosecutors plod through poorly kept, sometimes falsified records. In the end, their investigations often result in no action.

"I still have to live with the guilt that maybe I should have pushed somebody harder, tried harder, but I tried, I tried," said Helen McMakin after the death of her retarded stepdaughter Sandy McMakin in a state institution. "Everybody told us they would look into it, but I don't really believe anybody cared after she was dead."

For Daniels, a wheelchair user with a troubled mind and a crippled body, there has been no justice. Nor has there been any for many other victims, whose deaths have been under investigation for months, even years, without criminal or punitive action. Other cases include: * Lazaro Diaz, 32, who died last year from internal blood loss, a result of a broken thigh bone. No one at the Landmark Learning Center where he lived for 22 years could say how or when he broke his femur, the largest bone in the human body. The injury went untreated for 11 crucial hours. Diaz died waiting for an X-ray on a hospital gurney.