PITTSFIELD, Mass. (AP) _ A police academy cadet has died six weeks after he and two dozen other trainees fell ill from rigorous exercises, and his family's lawyer urged Thursday that the instructors be charged with manslaughter.

Timothy Shepard, 25, died late Wednesday at a Pittsburgh hospital where he had undergone a liver transplant operation. He was in a coma for two weeks, then emerged, only to lose consciousness again Monday.

Medical examiners said after an autopsy Thursday that Shepard died as a result of ''a chain of complications'' from the harsh training, which has been discontinued.

A formal state inquest into the death is planned, state Attorney General James Shannon said. He said he did not believe he had evidence to bring criminal charges, but added, ''There are potentially different legal consequences when death occurs.''

The family's attorney, Michael D. Hashim, described the Shepards as devastated. ''He came so close to making it,'' Hashim said.

Just four days before Shepard died, he had written his pregnant wife of five months, Holly: ''I'm going to make it.''

Hashim said the state troopers who oversaw the cadets' training at the Agawam academy should be indicted.

''I believe we have a clear-cut case of involuntary manslaughter here,'' Hashim said. ''They ignored conditions that placed the cadets in harm.''

Cadets' reports of hours of exercise on only a few cups of water sparked at least four state reviews and a shakeup of the agency that runs the state's regional police academies.

''There's no question in my mind that the event responsible for death was basically the physical exercise and water restriction that resulted in a chain of complications,'' Allegheny County Coroner Dr. Joshua Perper, who performed an autopsy, said at a news conference.

The cause of death was blood poisoning with abscesses of the liver and heart and hemorrhaging in the brain, chief state medical examiner Dr. Brian Blackbourne said late Thursday after attending the autopsy.

Blackbourne said Shepard had been weakened in the last few weeks by drugs meant to suppress his immune system so that it would accept his liver transplant.

''You have to take that risk sometimes,'' he said.

He said the infections that took hold may have caused a blood clot doctors removed, and hemorrhaging in Shepard's brain that they could not control.

Perper also said that a diet Shepard underwent in preparation for his training contributed to his susceptibility to liver damage.

The director of the state Criminal Justice Training Council resigned Wednesday and his replacement immediately abolished so-called stress training, a grueling program of intentionally confusing orders, verbal abuse and demanding exercise that was blamed in part for the cadets' dehydration and exhaustion.

Sixteen cadets were hospitalized during their first week at the academy, where state troopers trained recruits for police departments in western Massachusetts. Half the class of 50 suffered kidney ailments because of the training regimen, according to Shannon's report.

Gov. Michael S. Dukakis said in a statement: ''Nothing can make up for the Shepard family's loss, but they should know that the circumstances of this tragedy are of great concern to me. This administration is already moving swiftly to do all we can to ensure that it never happen again.''

Shepard never regained the strength to breathe and speak on his own after falling unconscious on a running track Sept. 19, but he communicated with his family in writing.

Friends and co-workers raised $10,000 for the young man voted Youth of the Year by the Pittsfield Boys' Club in 1981. His medical bills exceeded $330,000, according to Mayor Anne Wojtkowski.

''He was a kid with intestinal fortitude who wasn't a quitter,'' said James Mooney, executive director of the Boys' Club. ''He stood right up against the training and it killed him. He even showed his fortitude by clinging to life as long as he did. He never gave up. We've got to straighten out that system so young fellows don't have to go through that.''