BOSTON -- Who killed Carol Stuart?

In the year and a week since the young suburban lawyer, pregnant and on her way home from a birth class, was shot in the head on a deserted street in the city's Mission Hill section, the questions of who killed her and how remain legally open.

The case drew national attention as a tale of yuppie greed, big-city crime and racial mistrust. But when Stuart's husband, Charles, committed suicide and was blamed for the shooting, interest in the case faded for most white Bostonians. For many blacks here, though, the police manhunt for a black attacker who apparently never existed still rankles.

Some black leaders called for a "day of mourning" for the city's black community last week on the anniversary of the violent hoax that prompted police to invade the Mission Hill and Roxbury neighborhoods looking for a suspect.

Authorities said they now believe that Carol Stuart, 30, was killed by Charles, 29, a fur-store manager who apparently planned to cash in on her life-insurance policies. The couple's son, Christopher, was delivered prematurely and died 17 days after his mother.

In their best reconstruction of an event about which few facts have been proven, police say Stuart shot his wife on the evening of Oct. 23, 1989, then shot himself and tossed a bag containing the gun and some of her jewelry to his brother, Matthew, to make the incident look like a robbery. Divers recovered the bag and gun from a nearby river last January.

While his wife lay dying next to him in the car and as he also gushed blood, Stuart called police from a car phone and, they say, attempted to blame a raspy-voiced black man in a jogging suit for the shootings.

They say Carol Stuart's killer died last Jan. 4 when Charles Stuart jumped to his death from the Mystic Bridge into Boston Harbor. It happened just as police were starting to focus on him as a prime suspect in the deaths of his wife and son.

But questions persist, even about the most basic facts. Who pulled the trigger on Carol Stuart? Did Charles Stuart really shoot himself? Did he really jump off the bridge? Who threw the bag and gun into the Pines River?

One reason for the lingering suspicion is a legal dispute that has hampered a Suffolk County grand jury's effort to decide whether anyone now alive committed any of the crimes involved. Prosecutors want to question a last witness, John Dawley, an attorney representing Charles and other Stuart family members in January, when the apparent hoax was revealed.

But Dawley, one of the last people to talk to Stuart, has refused to testify, citing attorney-client privilege. The Massachusetts Supreme Court is deciding whether he can be forced to testify.

While guessing continues about the crime itself, many years of second-guessing may ensue about how police, prosecutors, politicians and the news media responded to the events.

A federal grand jury is expected to hear testimony soon on complaints by Mission Hill residents that Boston police pressured them last November and December into implicating a black man, William Bennett, in Carol Stuart's death.

Sadiki Kambon, director of the Black Information Network, a community activist group in the predominantly black Roxbury section, blamed the mayor and police commissioner for unleashing "a South African-style police attack on the greater Roxbury community that involved acts of overt terrorism" during the hunt for the alleged black attacker.

Bennett, 40, widely identified in media accounts here as a "prime suspect" in the case, was never charged. But he was forced into a police lineup, and Charles Stuart went so far as to declare that Bennett looked like the man he said had attacked the couple.

After Stuart leaped to his death, embarrassed officials cleared Bennett of suspicion in the deaths of Stuart's wife and child. But Bennett, already in custody awaiting trial on armed-robbery charges, remained behind bars. Earlier this month, he was sentenced to a maximum of 25 years in prison for a holdup in September 1989 at a video store.

Meanwhile, Carol Stuart's family, the DiMaitis of suburban Medford, have established a fund in her memory to provide scholarships to Mission Hill residents. The family's call for healing prompted more than $500,000 in donations, and the fund has awarded 33 scholarships.