Friend Opens Up After Woman, 2 Others Shot Dead at Grad Party: 'This Is a Nightmare'

Melanie Marshall says victim Anna Bui had broken up with the alleged shooter two months before.

The friend of a partygoer that was shot dead Saturday night outside Seattle is breaking her silence after the weekend bloodbath.

Melanie Marshall, who was victim Anna Bui’s best friend, told Inside Edition that she's still coming to grips with the tragedy that unfolded over the weekend.

Read: Teen Tech Whiz Arrested in House Party Shooting: Cops

“This is a nightmare. This is an absolute nightmare and I wish I could wake up from it,” she said.

Allen Ivanov, 19, is accused of shooting his ex-girlfriend, Bui, and two other partygoers.

Police say Ivanov was furious when he saw Bui with another guy at the crowded party in an affluent neighborhood.

Ivanov allegedly went to his car, grabbed an assault rifle he had purchased a week before, returned to the party and opened fire.

Bui, her friends Jake Long and Jordan Ebner were killed. Another teenager, Will Kramer, was seriously wounded.

Marshall says Bui was not happy in her relationship with Ivanov, which lasted about a year-and-a-half.

“She confided in my mom and she was telling her how she didn't feel comfortable in the relationship,” Marshall said. “She was very unsure about him.”

Bui recently returned home from a trip to Europe, and it was reportedly Ivanov's intention to resume their relationship.

Days before the shootings, he posted a photo of his new assault rifle with three bullets on social media.

He posted to Twitter: “First and last tweet. I've been through it all.”

He also left behind a long letter to his family and friends, telling his mom: “I wish I was everything you wanted. You're such a strong independent woman.”

Read: Supermodel's Billionaire Heir Son Arrested For Fleeing $28 Cab Fare: Cops

And to a friend, he wrote: "I’m sorry about that girl. Don't make the same mistake I made."

Ivanov was arrested in the ensuing hours following the shooting as cops say he sped down a freeway many miles from the grisly scene in Mukilteo, Washington.

Mukilteo Mayor Jennifer Gregerson addressed the press, telling reporters Saturday: "We grieve with the families who have lost those in this horrible event."

Watch: Cop Killed In Baton Rouge Ambush Wrote Chilling Post: I Get Nasty, Hateful Looks