WEST WARWICK — For Mark Jackson, a schizophrenic who died in a confrontation with the police, the state medical examiner’s office listed the cause of death yesterday as a heart attack, but it may not have been that simple.

When autopsy results were released, the medical examiner said Jackson’s illness made his heart beat faster than normal.

Annemarie Beardsworth, spokeswoman for the Department of Health, said, people who have schizophrenia are more likely to die suddenly and at a younger age.

“Two reasons for that,” she said, “are some of the longer-term medicines people are on, and also, people with schizophrenia, their baseline heart rate at rest is higher than a normal person’s heart. That can contribute to sudden death or a heart attack.”

Jackson’s heart was only part of the issue. Mental health advocates said that because of his illness, he may have lacked the social skills to get out of a confrontation, particularly the one he found himself in on June 27.

What the West Warwick police described as a scuffle that day ultimately led to Jackson’s death. “Three deaths in a year is a major wake-up call,” said Charles J. Gross, executive director of the National Alliance on Mental Illness of Rhode Island. “The police, mental health centers, advocates and families all need to be on the same team.”

That night, Jackson crossed paths with a pair of police officers behind Joyal’s Liquor Store, on West Warwick Avenue. The officers were responding to a call from a passing motorist who said she saw people damaging the store’s sign. When officers arrived, Jackson, who was staying with his mother in the apartment next door, was walking behind the store.

Jackson refused to remove his hands from his pockets when the police asked. The officers approached, and the three scuffled on the ground. Jackson got a shot of pepper spray. When that didn’t work, the police said, the officers used expandable batons to hit Jackson’s legs. Three more officers arrived before they were able to handcuff Jackson and put him into a cruiser. Jackson was unconscious in the back of the cruiser when the police arrived at headquarters minutes later. He was pronounced dead at a hospital. He was 47.

At least three people with mental illness have died in police custody this year in Rhode Island. Their deaths have forced officials and advocates to examine how the police interact with mentally ill people.

Schizophrenia, a neurological disease that often causes a loss of connection with reality, affects about 1 percent of Americans, according to the federal Centers for Disease Control and Prevention. Jackson was diagnosed with schizophrenia in the mid-1980s. He took medication for a time but in recent years had stopped.

According to Robert M. Swift, a professor of psychiatry at Brown University, schizophrenia itself wouldn’t cause the heart attack, but the lifestyle that people with the illness often live could have contributed to Jackson’s death.

Swift said that roughly 80 percent of people with schizophrenia smoke, compared to 25 percent of adult Americans without the disease. The medications used to treat schizophrenia often lead to weight gain, diabetes, high blood pressure and heart disease.

Jackson was a regular at a nearby Dunkin’ Donuts and at Joyal’s Liquor store, where he’d buy Phillies miniature cigars. He’d smoke them near the store’s loading dock. The medical examiner said Jackson had low blood flow from heart disease.

“With the stress of being restrained, someone is going to be upset, they’re going to be struggling,” Swift said. “Their heart is beating faster. The heart needs oxygen, but the blood vessels are clogged and it can’t get oxygen so it fails.”

On Feb. 12, Pawtucket police officers found Jason M. Swift, 30, outside his home brandishing a Samurai-style sword. The 30-year-old had previously suffered a nonviolent “nervous breakdown.” He was shot and killed.

On Feb. 27, Leonel Farias, 40, of East Providence, came out of the family home waving a steak knife at police officers. Farias, a diagnosed schizophrenic, struggled after he was handcuffed and pinned to the pavement. He lost consciousness and was pronounced dead later that day. Then, there was Jackson.

“His schizophrenia played a significant role in the outcome because he lacked the capacity to respond in ways to let the police know he was an innocent man walking home,” said H. Reed Cosper, of the state office of the Mental Health Advocate. “A person with a mental disorder, when confronted with a stressful situation, may react in ways that might make you think they’re a threat, even if they’re not.”

The attorney general’s office is investigating the incident. The release of Jackson’s cause of death does not implicate the West Warwick Police Department in any wrongdoing, said Michael J. Healey, spokesman for the office. The case will probably be heard by a grand jury, as are all police-related deaths, Healey said.

In September, 20 police officers from nine Rhode Island departments — including West Warwick — participated in a three-day training session through the state Department of Mental Health, Retardation and Hospitals aimed at teaching them how to deal with people who have a mental illness. Police Chief Paul A. Villa estimated the last training West Warwick officers received prior to that was in the spring of 2007.

“I think the training statewide has started to change now [following the deaths], which is good thing,” said Villa. “We’ve taken advantage of the training that has come out since these incidents. Prior to that, there wasn’t a lot of formalized training for police officers.”

The internal investigation into the incident, he said, is ongoing.

tbuford@projo.com