VAN NUYS, Calif. (KTLA) -- A new arrest was made Thursday evening in the 2009 shooting death of a Hollywood teenager resulting from a text message dispute.

Authorities arrested Hovik Dzhuryan, 19, the brother of Khatun 'Kat' Vardanian, the woman whom the slain 19-year-old Mike Yepremyan referred to as a "bitch" via text message, late Thursday evening at his home, alleging that he was an accessory in Yepremyan's November 2009 murder.

The alleged shooter, 23-year-old Zareh Manjikian, and Vardanian, the woman targeted in the text message, were previously arrested and charged.

Dzhuryan and his sister, Kat Vardanian, have both pleaded not guilty to conspiracy charges, according to the Los Angeles County district attorney's office.

Manjikian, and the man who allegedly struck the victim, Vahagn Jurian, are charged with murder. Both have also pleaded not guilty.

Authorities allege Manjikian shot Yepremyan in the back of the head just hours after the teen sent the insulting text message to his girlfriend, Denielle Wegrzyn, referring to her friend, Vardanian.

Wegrzyn was out with Vardanian at the time that the message was sent. She reportedly saw the text message and asked her brother, Dzhuryan, to beat Yepremyan up because of the insult.

Shortly after the text was sent, Yepremyan began receiving phone calls from a stranger asking him to come to the parking lot of the local Sears, according to reports.

Yepremyan agreed, bringing along his friends.

After exchanging a few words, one of the strangers produced a nine-millimeter handgun and fired one shot from behind Yepremyan's head, killing him instantly.

"It was literally two seconds of action, a bang, and you hear a car driving off," Mike's friend Ali Hosseini recalls.

The gunman remained on the run for 18 months until he was tracked down in Puerto Rico and arrested.

"To think: a boy sends a text message calling someone 'a bitch,' and within hours he's shot down in cold blood," says Beverly Hills private investigator John Nazarian.

Nazarian is working with the Yepremyan family on their son's murder.

Nazarian says Mike and his friends had no idea what they were getting into.

"This is a classic example of sheep going to a slaughter."

"In my professional opinion, Mike Yepremyan was targeted," Nazarian. "They went there with the intention of killing this child."

Mike's parents cling to their memories of their son. "He was my happiness, my joy," Mike's grieving mother Ani Atajyan told KTLA News.

Mike's mother Ani struggles to make sense of the violence. "To take somebody's life is so easy," Ani says. "Oh, you have a gun? Okay, that's it, he's gone. But what about after that? Did you think about what will happen to that family?"

"I don't have anything," Mike's father says. "It like a tree without roots, only leaves. Nothing, that's it."

And Ani's mother fights back tears in remembering her son. "My life is broken. Forever, forever."