A convicted Aroostook County sex offender was forced at gunpoint to swallow a fatal dose of prescription medicine last month by another sex offender, who later killed himself, according to the state medial examiner’s office, which released autopsy results Friday.

Deputy Chief Medical Examiner Mark Flomenbaum concluded that Lawrence Lewis, 68, of Molunkus Township died of “acute intoxication due to the combined effects of risperidone and nitroglycerin,” said a staffer at the medical examiner’s office, reading from the autopsy report.

The death was ruled a homicide and the report said Lewis was “forced at gunpoint to ingest an excess of prescribed medication.”

He was forced to take the medicine March 11 by an acquaintance, Bruce King, also known as Bruce Neal or Bruce Heal, 59, who shot himself later that day during a standoff with police.

Maine State Police spokesman Stephen McCausland said the autopsy confirms what police believed about the case — “that Lewis was forced to overdose on his medication and died as a result.”

“His body was then hidden in a location under a stairway in the house (the men shared) and then King … got into a standoff with police,” McCausland said.

McCausland said he had no new information about the case, which is still under investigation.

King had been scheduled to meet with a detective March 11 about an allegation that the convicted rapist and registered sex offender had sexually assaulted a young girl last year, police said at the time.

In an earlier interview, he told investigators that it was his former roommate, Lewis, who assaulted the girl.

Lewis’ body was found in his run-down home on Route 2 in Molunkus Township around the time King killed himself on Interstate 95 near Lincoln after a four-hour standoff with police.

Risperidone is a powerful antipsychotic medication that works by changing the effects of chemicals in the brain, according to the website drugs.com. It is used to treat schizophrenia and symptoms of bipolar disorder, also called manic depression.

The website includes the following warning: “Risperidone is not for use in psychotic conditions related to dementia. This medication may cause heart failure, sudden death, or pneumonia in older adults with dementia-related conditions.”

In addition to being an explosive, nitroglycerin is used as a medicine to treat heart conditions.

Dr. Karen Simone of the Northern New England Poison Center had no knowledge of the case specifically, but said both risperidone and nitroglycerin can cause a sharp drop in blood pressure. That can lead to a sudden rapid heartbeat or other complications, which in an unhealthy person could be fatal.

The autopsy showed that Lewis had high blood pressure and clogged arteries.

Before he took his own life, King told Penobscot County Sheriff’s Deputy Patty McLaughlin that he had killed Lewis by forcing him to overdose on prescription medication, according to a police affidavit.

The cause of King’s death was listed by the medical examiner’s office as a single gunshot wound to the neck and head.

The incident on March 11 started when police stopped a southbound U-Haul truck driven by a woman on I-95. Lynda Fogg, 43, of Mattawamkeag — also known as Lynda Dube and Lynda Gordon — got out of the truck and told police that King, who was in the passenger seat, had been holding a gun on her.

A court affidavit said a deputy talked to King by cellphone. During that conversation, King said he had killed Lewis, his former roommate, because Lewis was molesting children and nobody was doing anything about it.

The affidavit said a man identified as Mark Vieria informed police that King told him he had found pictures and videos of Lewis engaged in sex acts with children. The affidavit did not say how Vieria knew King. McCausland said he doesn’t know what their relationship was.

Lewis was convicted in 1992 of raping a 9-year-old boy. He served several years in prison but had not been suspected in any sex crimes since then, police said.

King was convicted of rape and was listed as a registered sex offender in Massachusetts. The Massachusetts Sex Offender Registry Board’s website lists a Bruce King who was convicted of rape in Salem, Mass., in 1985. It says he was a Level 3 sex offender, someone who poses “a high risk to re-offend and … the degree of dangerousness posed to the public is such that a substantial public safety interest is served by active community notification.”

He had not registered with Maine officials.

David Hench can be contacted at 791-6327 or at:

dhench@mainetoday.com