QUINCY, Ill. (AP) _ A doctor accused of poisoning co-workers with arsenic-laced snacks cheered when a gunman massacred 21 people at a McDonald's restaurant in California, a prosecutor said Monday at the physician's trial.

Dr. Michael Swango ''was enamored with people being hurt, people who were unsuspecting,'' Assistant Adams County State's Attorney Chet Vahle said in opening arguments.

Swango, 30, ''was entranced by trauma, the thrill of emergency scenes,'' Vahle said.

Swango is accused in the non-fatal poisonings of six colleagues last summer and fall, when he worked as a paramedic for the Adams County Public Health Department while awaiting medical licensing in Illinois and Ohio.

Swango denies the charges.

His attorney, Daniel Cook, said in brief opening arguments that the state's case was an accumulation of ''guesses, hunches.''

Swango was a neurosurgery resident at Ohio State University Hospitals in Columbus from mid-1983 until June 30, 1984. Although he has not been accused of any wrongdoing there, authorities say he is under investigation in the deaths of about a dozen hospital patients.

Illinois has suspended Swango's medical license and Ohio has begun similar proceedings.

Swango's nonjury trial on seven counts of aggravated battery charges is expected to last until next week. Each count carries a maximum penalty of seven years in prison.

The first witness, one of six alleged poisoning victims, testified that Swango once described what he considered ''the ultimate (emergency) call.''

In it, county emergency medical team-member Brent Unmisig told the court, Swango said a school bus would crash into a gasoline-filled tanker truck, and an explosion would hurl children's burning bodies into utility poles and onto barbed-wire fences.

''He had a serious look on him'' when he described it, Unmisig said.

Swango once told a fellow paramedic, '''I feel I have an evil purpose,''' Vahl e said.

While watching coverage of the San Ysidro, Calif., McDonald's massacre last summer from the paramedics' quarters, Vahle said Swango ''became excited to the point of turning the (television) volume up, jumping out of his seat and calling others to watch, and cheering.''

Once, while discussing serial killers, Vahle said Swango told a co-worker: ''I really admire those guys, going around the country killing people.''

Swango's preoccupation with mayhem was his motive for slipping ant poison containing arsenic into doughnuts, tea and other snacks he served co-workers last fall, Vahle said.

Swango was arrested Oct. 26 after fellow paramedics became suspicious about several bouts of sickness that followed his serving them snacks and drinks, Vahle said.

The prosecutor said detectives who searched Swango's apartment two days later ''were confronted with a veritable laboratory of poisons,'' including packages of Tero Ant Poison, a syringe containing an arsenic-based substance, ''recipe cards'' for exotic poisons, as well as a revolver, a 12-gauge shotgun and knives.