Employee allegedly killed by client at Revere mental health facility

Authorities did not disclose today how Moulton was killed. Chappell will be arraigned on Friday in Chelsea District Court.

‘‘We are just devastated,’’ said Jackie Moore, chief executive officer of North Suffolk Mental Health Association, which operates the group home at 110 Ocean Ave. for the state. ‘‘She was a beautiful and vibrant young woman. She loved her work and loved our clients.’’

Moore said her agency, in business for 50 years, has occasionally recorded altercations between staff and patients, but nothing of this magnitude. She said they run training sessions to make sure staff know how to protect themselves and reduce risks.

‘‘Safety is something we take seriously,’’ she said. ‘‘There have been isolated incidents, but nothing this violent or tragic.’’

Moore said she has no idea what triggered the violence against Moulton, and she has no evidence that the victim and suspect had anything beyond a counselor-client relationship. At the time she was attacked, Moulton was likely to have been the only employee at the group home, which lodges up to five men with mental illness. Moulton’s job called for her to oversee the food and other day-to-day needs of the residents, as well as monitor psychiatric medications and other therapeutic services.

Suffolk District Attorney Daniel F. Conley, at a press conference today, said Chappell was ‘‘known to police,’’ and Moore also said that Chappell was known to her agency for ‘‘a number of years’’ due to his involvement in more than one of its programs.

A man who answered the phone at a number listed for a relative of Chappell’s in Arizona declined to discuss Chappell or the case tonight.

‘‘How do you know he did it or not?’’ said the man, who would not give his name. ‘‘I’m just going to find out what happens as it happens, because no one really knows, so how can anyone comment?’’

The young woman’s death illustrates the potential risks taken by clinicians and staffers who work with the mentally ill, including those who have been deemed safe enough to live in their communities rather than in locked institutional settings.

Nearly three years ago, a social worker, who was part of a program to help troubled adolescents stay in their homes, was killed by a North Andover teenager in her care. In 2001, a man killed a social worker who stopped by his Cranston, R.I., apartment to deliver psychiatric medicine.

Susan Tousignant, head of local 509 of the Service Employees International Union representing 12,000 state human service workers in Massachusetts, said her staff always worries about safety, but emphasized that this type of client-on-staff violence in group homes ‘‘is very unusual.’’

She said the overwhelming majority of her workers are not showing up at work frightened about being injured. Still, she and others said that employees working with such patients must be sure to undergo rigorous training to ward off possible risks.

John Labaki, a mental health counselor and the union official in charge of mental health workers within local 509, said management and union officials have created a task force to study a range of issues to reduce dangers in all psychiatric settings, including mental hospitals. A top priority, he said, is ‘‘How can staff come to work and feel safe?’’

Union officials said Moulton did not belong to local 509.

Conley said Revere police and fire responded today to a facility at 110 Ocean Ave. in Revere shortly before noon for a report of a fire. They discovered a large amount of blood ‘‘consistent with a violent assault’’ as well as a small fire — but no apparent victim.

‘‘A short time later, Lynn police and State Police assigned to the Essex district attorney’s office responded to the area of 54 South Common St. [in Lynn] for a found body,’’ Conley said.

Meanwhile, police put out alerts that they were looking for a PT Cruiser in connection with woman’s disappearance. A car matching that description was found parked near the Ashmont MBTA bus and Red Line station this afternoon.

Later in the evening, acting on information, police tracked the suspect down inside the Roxbury apartment building, and he emerged outdoors in handcuffs shortly before 8 p.m.

Jennifer Kritz, spokeswoman for the state Executive Office of Health and Human Services, which oversees the Department of Mental Health, said in a statement tonight that ‘‘we grieve this terrible tragedy with our provider partner and want to express our concern and condolences to her family, friends and co-workers.’’

Conley referred to the case as ‘‘an extremely violent homicide of an innocent young victim.’’

Travis Andersen can be reached at tandersen@globe.com and Patricia Wen at wen@globe.com.