As prosecutors try to put his only child behind bars for life, John C. Salvi Jr. sits on a hard court bench enduring the worst winter of his life.

His son, John C. Salvi III, is accused of killing two people and wounding five others at two suburban Boston abortion clinics in December 1994. The elder Salvi has watched virtually every minute of the trial, now entering its sixth week."This is the hardest winter I've ever been through," he said one snowy day last week during a break in testimony.

His son's attorneys, who were expected to wrap up their case Monday, admit Salvi was the gunman but claim he was insane.

Prosecutors, who plan to cross-examine a psychiatrist key to the defense Monday, say the killer was too methodical in planning the attacks to be anything but sane.

John Salvi Jr., 50, and his wife, Ann Marie, have been staying in icy Massachusetts, far from their home in sunny Naples, Fla., to be closer to their 24-year-old son.

His wife doesn't go to court every day.

"I can't say she's doing great, but she's doing all right," Salvi said.

Early on, he took the witness stand and told jurors how his son changed toward the end of high school, withdrawing from friends and spending hours alone reading the Bible.

Last week, he politely declined to discuss the case.

In court, he passes the family of Shannon Lowney and, some days, the fiancee of Lee Ann Nichols - survivors of the two women his son killed at the Planned Parenthood and Preterm Health Services clinics in Brookline. They sit on opposite sides of the courtroom.

If convicted of first-degree murder, John C. Salvi III faces mandatory life in prison without the possibility of parole. If acquitted by reason of insanity, he will be committed to a state hospital until deemed sane.

Regardless of the outcome, defense attorney J.W. Carney Jr. doubts his client will ever be free.

"He stands about as much chance of getting released as Charles Manson does of being paroled. Some people are just so notorious they will never be released," he said.