The 21-year-old man accused of fatally shooting his girlfriend, two of her family members and his parents in two separate shootings in Ascension and Livingston Parish Saturday morning is considered armed and dangerous and authorities believe he is on the move. 

UPDATE: Sunday, Jan. 27 at 8:05 a.m.: Dakota Theriot has been found in Richmond, Virginia, and arrested.

Dakota Theriot is wanted on multiple counts of first-degree murder, illegal use of weapons and home invasion, authorities said.

He is reportedly driving a 2004 Dodge pickup truck that's gray on top and silver on the bottom with a license plate number of C583809 and an LSU sticker on the back window. Officials believe he took the truck from the family he shot in Livingston parish. Livingston Sheriff Jason Ard said Saturday afternoon that he did not believe Theriot was still in Livingston Parish, and later that night he said officials did not have a general location for Theriot.  

“We have indication that he’s traveling east of here, maybe in another state," said Ascension Sheriff Bobby Webre at a press conference late Saturday. “Our commitment ... is we will use all of our resources to bring this murderer to justice.”

Theriot is suspected of shooting and killing his girlfriend, 20-year-old Summer Ernest, her father Billy Ernest, 43, and her brother Tanner Ernest, 17, at their mobile home in the 14600 block of Courtney Road just outside of Walker in Livingston Parish just before 9 a.m., according to neighbors and authorities. 

Shortly after, he drove 25 miles south to Ascension Parish where he shot his parents, Elizabeth and Keith Theriot, both 50, at their home in the 42000 block of Churchpoint Road in Gonzales. 

Webre said that Keith Theriot was able to identify his son as the shooter before he died Saturday. Keith Theriot was alive but gravely injured when deputies first arrived at the Gonzales area home. 

Webre said Theriot has two tattoos, one of a cross on his chest and one of a yin and yang symbol on his right forearm. Theriot was last seen in a blue sweatshirt and official believe he is armed with at least one handgun.

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Little is known of Theriot at this time, including a motive for why he carried out the shootings, but a short history of contention between him and his parents was detailed by authorities and neighbors.

Webre said Theriot lived with his parents at their Gonzales home previously, but was recently asked to leave due to some disagreements. A neighbor, Michael Logan, said he had heard arguing and "yelling matches," usually at night, coming from the home lately. 

Charlenne Bordelon, a neighbor to the Ernests, said the family was friendly and were good neighbors, but she did not know much about Theriot, who had moved in with the Earnest family a few weeks ago. However, she had never seen any problems or heard arguing.

Billy Ernest's wife, who was at work during the deadly rampage, told authorities that she had no prior concerns about Theriot, who had been living with their family. The family's two youngest children, aged seven and one, were also home at the time of the shooting, but were not injured. 

Officials with both Livingston and Ascension Sheriff's Offices also said there were "no red flags" from Theriot's past and he was not on their radar for suspicious or dangerous behavior. Livingston Sheriff Jason Ard said Theriot had been arrested once in their parish for possession of drug paraphernalia. He had never been arrested in Ascension and authorities had never before been called out to the Theriots' residence. 

Theriot had also been arrested in April 2017 in St. Charles Parish for marijuana possession and fleeing authorities. Officials reported that Theriot sped away from deputies during a a traffic stop where he was asked to step out of his vehicle. The Advocate could not find any other information on Theriot's criminal history on record of violence.

Advocate staff reporter Grace Toohey and correspondent Olivia McClure contributed to this report.