MIAMI (AP) _ The former wife and son of the Democratic candidate for state attorney general were found shot to death on a downtown street Monday, and police said they were looking into the possibility the two died in a murder-suicide.

Police would not release the identities of the victims, but campaign spokesmen for Bob Butterworth confirmed it was his ex-wife, Sandra, and 16- year-old son, Robert Jr..

Robert, who was shirtless, was found shot several times in the chest. Sandra Butterworth, shot once in the head, was found a few feet away, sprawled on the sidewalk next to a public telephone booth, police said.

''We're investigating a shooting. It could be a murder-suicide. That's what we're looking into,'' said police Sgt. Jerry Kaline.

Police are investigating whether a hysterical woman who called about an hour before the bodies were found was Mrs. Butterworth, said police spokeswoman Cori Zywotow. A tape of the call will be examined, she said.

''It could mean that she killed her son and then herself, anything is possible,'' Ms. Zywotow said.

A .38-caliber revolver was found next to the body of the woman, who suffered a gash to her forehead, she said. The young man was shot three times in the chest and once in the neck.

Butterworth could not be reached for comment.

''Bob and his family are together as families should be right now and they're shocked,'' said Butterworth's campaign spokesman, Ron Villela.

''We really don't have any details,'' said Pat Rathburn, an associate of Butterworth's who was contacted at his campaign headquaters in Hollywood.

''It is a tremendous tragedy for all of us,'' she added. ''Bob and other members of his family have gone into seclusion and are sure the people of Florida will understand.''

Butterworth, 43, is running on the Democratic ticket against Republican Jim Watt. He served as a county judge from 1974-78 and briefly as a circuit judge in 1978.

He was appointed in December 1978 to complete the term of Broward Sheriff Ed Stack, who was running for Congress. Butterworth was elected to one four- year term as sheriff in 1980, but stepped down in 1982 when Gov. Bob Graham asked him to become director of the state Department of Highway Safety and Motor Vehicles.

He returned to Hollywood to practice law in 1983, but Graham called on him again in 1984 to take over when Sunrise Mayor John Lomelo was indicted on bribery charges. When Lomelo was convicted, Butterworth declined to run for the job and returned to his law practice.

Butterworth finished second in the first Democratic primary, but forced state Sen. Edgar Dunn into a runoff. He won by 1,938 votes in the Sept. 30 runoff.