A 21-year-old man accused of shooting and killing five people in Louisiana over the weekend has confessed to authorities, officials said Tuesday.

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Livingston Parish Sheriff Jason Ard told reporters at a news conference Tuesday that Dakota Theriot confessed to killing the victims Saturday in Livingston and Ascension parishes, using a gun he said he stole from his father.

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Authorities said that on Saturday morning, Theriot rode with 50-year-old Billy Ernest as the older man drove his wife to work. After they returned to the Ernests’ home in Ascension Parish, Theriot opened fire, killing Billy Ernest, 20-year-old Summer Ernest and 17-year-old Tanner Ernest. He then drove to Ascension Parish, where authorities said he shot and killed his parents, Keith and Elizabeth Theriot, both 50.

Ascension Parish Sheriff Bobby Webre said Keith Theriot survived the shooting long enough to call 911, and when deputies arrived he told them just before he died that his son had shot him.

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“We don’t know what the motive is – we just know what he did,” Ard said Tuesday at a news conference.

Authorities said Dakota Theriot started living with the Ernests about two weeks before the shooting after he was apparently kicked out of his parent’s home. Deputies believe Dakota Theriot was dating Summer Ernest, although Ard noted that their relationship lasted only a few weeks.

“We don’t know if we will ever have a motive (for) exactly why this happened,” Webre said Tuesday.

Dakota Theriot was arrested Sunday after authorities said he drove to his grandmother’s house in Richmond County, Virginia. Authorities knew he had family in the area and deputies were waiting for Dakota Theriot when he arrived, Ard said. After a brief confrontation, Ard said Dakota Theriot put down his weapon and surrendered to authorities.

He is expected to appear in a Virginia courthouse Friday morning for an extradition hearing. Webre told reporters Tuesday that he could be transferred to Louisiana as soon as that day, if he decides to waive his hearing.

Authorities continue to investigate.

The Associated Press contributed to this report.