Video Shows Moment Man Accused of Killing His Two Teenage Brothers Was Arrested

Family members and friends told police Seth South admitted he "killed the boys" -- one of whom's throats was sliced -- and was en route to murder a third brother before he was apprehended.

A man accused of killing two of his younger half-brothers before possibly planning to murder a third has been arrested in Washington state.

Seth South, 23, was charged with suspicion of two counts of murder in the second-degree and third-degree assault of an officer, after he was apprehended by the Pierce County Sheriff's Department on a warrant out of Kitsap County on Wednesday night.

While the murder charges stem from the deaths of his brothers, ages 16 and 17, the assault charge, per the sheriff , "is the result of South attacking a Kitsap County Sheriff's Detective as he was being transferred from Pierce County custody to be transported to Kitsap County. The detective suffered minor injuries."

His arrest can be seen below:

Double Murder

The hunt for South began earlier in the day, after he allegedly called police and said one of his half-brothers had slit his own throat -- this according to docs cited by FOX 13 . The phone went silent, before the dispatcher reported hearing fighting in the background, followed by more silence.

When troopers from the Kitsap County Sheriff's Office arrived on scene, they observed a body face-down on the kitchen floor through the window, before entering the home and finding one of the half-brothers dead. The body of another brother, whose throat was cut, was then found sitting "in an unusual position" at the top of the stairs on the second floor.

Two knives were found near the body in the kitchen, while guns were also recovered at the scene.

With authorities determining the two teens died "by homicidal means," a warrant was then issued for South's arrest -- as the sheriff publicly announced they were looking for him and his 2018 Tacoma. "He is believed to be armed and should be considered dangerous," the sheriff said in a release before his arrest.

According to the Kitsap Sun , citing docs, a grandparent got South on the phone and was told by the suspect, "You're with me or you're against me" while saying he "killed the boys." He also allegedly denied killing anyone while speaking to a different family member ... and admitted to killing someone to someone else, but didn't mention who. Someone also told authorities he was heading to Missouri, to kill another brother who lived out of state.

When South was apprehended, blood and bloody clothes were allegedly found inside his vehicle. When speaking with authorities, South also allegedly admitted to stabbing and slashing one of the victims, but claimed that victim killed the other brother. The three all reportedly lived together in the same home.

Per KING 5 , South appeared in court on Thursday and was ordered to undergo a competency evaluation by the judge. He's still being held in jail.

Teen Emotionless in Court Violently Beat Grandmother to Death for 'No Apparent Reason': Police