For Daniel McLatchie, caring for his autistic son, Benjamin, was a demanding full-time job. He worried what would happen if he were gone.

Police say that apparently was why he shot his 22-year-old son with a shotgun Tuesday in the driveway of the family’s home in Gray, then shot himself. The state medical examiner confirmed Wednesday that the deaths were a murder-suicide.

Police say Daniel McLatchie, 44, left two notes: one expressing fear about his son’s future care, the other with financial information for his wife, Allison, Benjamin’s mother. At the time of the shooting, she was working at a school for children with developmental disabilities.

Police got a 911 call summoning them to the home. They believe the call was made by Daniel McLatchie just before the shooting.

Caring for people who are autistic can be an extremely stressful job and take an immense toll on even the closest of family members, experts say. At the same time, state services for adults with cognitive disabilities like autism are limited, and often have waiting lists.

Benjamin McLatchie may have recently become too old for school-based services, which end at age 21.

People who know the McLatchies declined to talk Wednesday about the family’s circumstances. Students of severe autism, however, said it can be a challenge for families to provide constant care for a child with extensive needs.

“A lot of times they’re non-verbal, meaning they have very limited communication,” said Julie Alexandrin, associate professor of special education at the University of Southern Maine and coordinator of the abilities and disabilities study program. “If you can’t communicate well, you’re more prone to have behavioral problems, much more acting out behavior, because they’re frustrated.”

Low-functioning autistic people can need help with basic personal hygiene and bathroom needs, and many can’t entertain themselves for even short periods, she said. “It’s kind of like, nonstop, being with a very young child who doesn’t take a nap,” Alexandrin said.

There can be costly medical issues that are not covered by insurance, particularly if coverage was not available because the autism was a pre-existing condition, she said.

Getting help is difficult, especially after children grow out of school-based services.

“It can be a one- to two-year wait list to get into a day treatment program, and it can be that long or longer to get into a group home,” she said.

Parents often fear that when they die, there will be no one to care for their disabled children.

Cathy Dionne, director of programming and administration for the Autism Society of Maine, said that knowing what services are available and accessing them can be a challenge.

“If you have a child with non-verbal, self-abusive behaviors and a lot of sensory issues (who) is getting no services because they are out of school, think about dealing with that 24-7 as a stay-at-home dad,” she said.

“The stress level is high. I can say that as a parent” of an autistic child, Dionne said.

The state Department of Health and Human Services lacks funding to serve every disabled person who needs them, and must prioritize.

All people with cognitive developmental disabilities should have access to case management services, said Jane Gallivan, director of the Office of Adults With Cognitive and Physical Disabilities in the DHHS.

“If someone was in significant jeopardy and really needed to leave their family home, we would help them to transition into a home outside their family home,” she said, in circumstances including complex medical issues or exhausted parents.

But there has been a waiting list, she said.

“The residential settings are costly. We have to make sure we’ve given those precious dollars to the individuals in greatest need of those services,” Gallivan said. If someone cannot care for themselves and has no family to provide that care, the state is obligated to take them in.

The Legislature approved additional funding for this year, so some new residential slots will open up this summer, she said.