NEILLSVILLE, Wis. (AP) - No physical evidence links the unsolved slaying of a deer hunter four years ago to a Minnesota man convicted of killing six northern Wisconsin deer hunters last fall, Clark County Sheriff Louis Rosandich said Friday.

It will likely take a confession to solve the slaying, he said.

Chai Soua Vang, a 36-year-old Minnesota truck driver, is considered a "person of interest" in Jim Southworth's death, based on some similarities to the murders that Vang was convicted of last week in Sawyer County, Rosandich said.

Clark County investigators have not talked to Vang but want to ask him where he was on Nov. 23, 2001, when Southworth, 37, of Medford, was shot twice in the back near his tree stand on family land east of Neillsville, the sheriff said.

Three Asian men and a white pickup truck reportedly were seen in the area where Southworth was hunting, Rosandich said.

Investigators believe Southworth was murdered and not the victim of a hunting accident because he was shot twice in the back after apparently leaving the tree stand, the sheriff said.

No date has been set for Vang to be interviewed by Clark County investigators and it will only be done if Vang's attorneys allow it, Rosandich said.

"It would be nice if he would have any information. But it is going to be quite difficult to solicit any information from him," the sheriff said.

A week ago in Hayward a jury convicted Vang of six counts of first-degree intentional homicide and three counts of attempted homicide in the killing of six hunters and wounding two others Nov. 21.

Vang, a Hmong immigrant, faces mandatory life in prison for each of the murders.

Mary Lokken, an assistant to Sawyer County Circuit Judge Norman Yackel, said Friday that the judge is comparing schedules with attorneys in Vang's case in an attempt to select a sentencing date in early November. Until then, Vang remains in the Sawyer County jail.

The killings occurred after Vang was found in a tree stand on land owned by some of the white hunters in southern Sawyer County about 100 miles north of Neillsville.

Vang testified he fired in self-defense after a hunter angrily confronted him, using profanity and racial slurs, and a shot was fired his way. Two survivors testified that some angry words were exchanged with Vang but he walked away from the group, took the scope off his semiautomatic rifle, turned and started firing at them.

Four of the victims were shot in the back, some multiple times as they tried to run away.

The shootings occurred on private land surrounded by acres of public land - a circumstance similar to the Southworth killing, Rosandich said.

According to the sheriff, the gun seized from Vang after the Sawyer County shootings - a black, Russian-made 7.62mm SKS rifle - is of little value in helping solve the Clark County killing because no bullets were recovered from Southworth's body.