On his bad days, Adam Bertman would crush light bulbs with his bare hands. He once launched the heavy lid of a toilet tank down the stairs, striking a caregiver.

One of his worst days came in fall 1998, when Bertman, who has autism and brain disease, became upset while out for a supervised walk. He started throwing rocks at cars and was so out of control by the time police officers arrived that they pulled their guns.

That was Bertman’s life before he entered the Northern Virginia Training Center in Fairfax, one of the commonwealth’s five state-run institutions for the developmentally disabled. It was before he developed relationships with the center’s staff members, who have learned to read his body language for signs that he is becoming agitated.

But now, as the state prepares to close four of the five centers and move their residents to community-based group homes, his mother, Judith Korf, worries that Bertman, 41, will end up in the same situation again.

She and other family members are fighting the plans, arguing that their loved ones, many of whom are so disabled they have problems with basic functions, such as swallowing food, need far more care than they will probably get in community settings. Indeed, Bertman is not the only one at the Fairfax center who landed there after community placements failed.

“When I think about what’s going to happen when the training centers are gone — I just don’t even want to think about it,” said Korf, who is 69 and lives in Reston. “For Adam, I think the past has shown that this is the only thing that works.”

Virginia is among the last states to begin dismantling its large institutions for the developmentally disabled, a decision that was made as part of a year-old settlement agreement with the Justice Department, which argued in a lawsuit that Virginia was discriminating against training center residents by keeping them institutionalized. All but one of the commonwealth’s five training centers, as the state calls them, are to be shuttered by 2020, with the one in Fairfax set to close by July 2015.

The state has touted the plan as the best thing for the approximately 18,000 developmentally disabled Virginians who are receiving or waiting for services: Training center residents get to move into the community to homes that will meet their needs, and with the money that is saved by closing the centers, the state can begin to make a dent in its waiting list. About 7,400 families are in line for services or group-home placement, and many have been waiting for years.

Jim Stewart, commissioner of the Virginia Department of Behavioral Health and Developmental Services, said the population at the training centers has been decreasing for decades, from nearly 6,000 in the 1970s to about 900 today.

“What’s happening now,” Stewart said of the plan to get rid of the centers, “was already happening” on its own.

State officials said they are confident that the training centers’ residents can be properly cared for in the community, and they note that no one will be forced to accept community placement. For guardians who insist on a training center, the state is keeping open one center in Chesapeake, with 75 beds.

But even among those who think the training centers should be shuttered, there is deep concern that the state is rushing the process to meet unrealistic, arbitrary closure deadlines. The biggest problem, according to many county officials and some Virginia legislators, is that there are not enough group homes to receive the training center residents. Most existing homes are full, and little has been done to set up new ones to add capacity.

The families who are fighting the closures got a small boost last week when two General Assembly subcommittees made recommendations that could slow the process and give legislators more oversight, but the measures have yet to be approved. For now, the state and the centers are proceeding with the closures as planned.

Peter Kinzler, whose 38-year-old son, Jason, has lived at the Northern Virginia Training Center since he was 3, said providing the safest environment possible should take precedent.

“They’re putting ideology over what we know is best for our child,” he said.

Jason has Angelman syndrome, a rare and complex neuro-genetic disorder. He is extremely medically fragile and functions cognitively at about the level of a 6-month-old. He constantly puts things in his mouth — he once ate 11 inches of a blanket — and because he cannot communicate, close monitoring of his health is often the only way to know when something is wrong.

County officials said more group-home capacity has not been added partly because Fairfax has some of the most expensive real estate in the country, and Medicaid funding is inadequate, so few private group-home operators are interested in expanding.Some believe nothing will change without state incentives or intervention.

“We know for a fact that the community is not ready to absorb these residents,” said Del. Eileen Filler-Corn (D), whose district includes the local training center.

Korf fears it will never be ready for her son.

When he was young, she had hoped she could care for Bertman at home until transitioning him into a group home. But over time, he became too strong, too aggressive and too unpredictable.

He has no major physical deficiencies and understands almost everything that is said to him, but his verbal skills and his willingness to use them are limited. He is easily overwhelmed and agitated and prone to destructive outbursts. He constantly tests limits and is the most stable when he knows someone else is firmly in control.

At the Northern Virginia Mental Health Institute in Falls Church, where Bertman spent more than a year, the staff dealt with his behavior by sedating him, Korf said. At two group homes, his caregivers were unable to keep Bertman and those around him safe. He went on rampages, threw the toilet tank lid and crushed the light bulbs.

With all other options exhausted, Bertman finally was granted a spot at the training center 14 years ago, when he was 27. He lives with three other men who have at least two staff members with them at all times. He receives recreational, occupational and speech therapy. When he feels up to it, he swims and does art projects. His favorite thing, which his caregivers indulge, is visiting the airport to watch planes come and go.

He still has bad days, but they are less frequent and eruptive than they once were. Korf credits the structure and stability of his life at the training center, along with the staff, who have come to understand Bertman.

On a recent day, he agreed to show a visitor his room, which is decorated with race cars and mementos from Special Olympics competitions, but after a few minutes he became tense. “He needs some space,” a staff member said when he noticed Bertman’s face tighten. “Let’s just step out and give him a minute.”

Korf once agreed that all institutions for the developmentally disabled should be closed. The Northern Virginia Training Center changed her mind. She said she worries that in a group home Bertman will regress and, after a few bad incidents, he will become more isolated from the world than he is now, not less.Or worse, he will end up hurting himself or someone else.

As if to reassure her, the staff that is planning the training center discharges have told Korf that Bertman will probably be among the last to be moved.

But Korf finds no comfort in it.

“I think what they’re really saying,” she said, “is that they have no clue what they’re going to do with him.”