Allen Ivanov, who killed three of his teenage friends last July when he opened fire at a Washington state house party, was sentenced Thursday to life in prison without parole.

Ivanov, 20, repeatedly apologized to the families on Thursday for killing his former girlfriend, Anna Bui, and friends Jacob Long and Jordan Ebner, all 19.

But he blamed current gun laws and 'Satan' for his actions.

'Satan was in control', he said. 'I did not intend for events to unfold the way as they did that night. In a moment of shock, I pulled the trigger because I could not control my emotions'.

Court documents portrayed him as a young man distraught over his breakup with Bui, who he considered his 'dream girl'.

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Hung Bui (left) fights back tears with daughter Anny Bui during the sentencing for Allen Ivanov

Ivanov, 20, was sentenced Thursday to life in prison without parole for killing his former girlfriend, Anna Bui, and friends Jacob Long and Jordan Ebner, all 19

Bui's sister, Amy, sobbed at Thursday's hearing as she told Superior Court Judge Janice Ellis that the murder had destroyed her family, the local Everett Daily Herald reported.

The families of the other victims expressed anger and sorrow over the horrific murders during a nearly three-hour testimony.

Autumn Snider, the mom of Jacob Long, brought the urn containing her son's ashes with her to the courtroom.

'I no longer have Jake with me in person, which is why I chose today to bring him with me. This is what I have left of my son'.

Isanov addressed the packed courtroom on Thursday, reading a prepared statement:

'There is no justification for what I did. I am so, so sorry for causing all of you to be here today'.

In Ivanov's statement on Thursday, he repeatedly apologized 'wholeheartedly' for the shootings, but blamed current gun laws and Satan for his actions

He opened fire at a house party in July in Mukilteo, Washington, a small town near Seattle

The former University of Washington-Bothell student also shot at Tristan Bratvold and Alex Levin as they ran for safety. A fourth victim, Will Kramer, was shot in the back but survived.

Kramer was with his dad Paul in the front row of the courtroom on Thursday.

'It is incomprehensible how a young man from our community could do something like this', Paul Kramer said.

The gunfire at the Mukilteo, Washington, house party lasted only about 35 seconds.

But it affected so many people in this small, tight-knit community, where teens often graduate with the very same people they entered kindergarten with.

Mukilteo resident Sherri Parker said the affluent town, 25 miles north of Seattle, has been left in a state of shock.

The former University of Washington-Bothell student pleaded guilty on December 19 to three counts of aggravated first-degree murder and two counts of attempted murder

He had told friends he was thinking about harming Bui because he was upset that she seemed to be moving on after their breakup

On the night of the murders, Ivanov crept outside of the house in the waterfront Chennault Beach neighborhood with an AR-15 rifle and two magazines

‘It just shows this sort of thing can happen anywhere,' Parker said.

Months later, the community is still coming to terms with the fact they'll never see their friends and loved ones again.

Ivanov pleaded guilty on December 19 to three counts of aggravated first-degree murder and two counts of attempted murder.

Prior to the murders, Ivanov wrote a six-page letter explaining his motivation. He was upset that Bui had moved on with her life and had begun dating other men after their breakup two months prior.

She was the first girl he had kissed, he told police.

'I’m selfish. That’s why I did this', he wrote.

Bui was one of three people killed during a horrific mass shooting at a house party in Mukilteo, Washington on Saturday. The alleged killer is her ex-boyfriend

Jordan Ebner, a student at Everett Community College, also lost his life in the horrific mass shooting

Jake Long (pictured with his girlfriend at prom) was the third victim of the tragedy that has rocked Mukilteo

Will Kramer, 18, (pictured left) was injured during the shooting. He is currently in serious condition

He had told friends he was thinking about harming Bui. They urged him to seek help and to get rid of the AR-15 he had purchased a week earlier.

On the night of the murders, Ivanov crept outside the $1million house in the waterfront Chennault Beach neighborhood with the rifle and two magazines, according to court documents.

He saw a male running toward the house and shot him.

Ivanov went to a balcony off the master bedroom and shot two more males.

Hundreds of students gathered at Kamiak High School in July to pay tribute to the three victims

Kamiak residents said Jordan, Jake and Anna were well-liked, and all friends with each other

Devastated students could been seen crying in disbelief as they remembered their former classmates

Two girls embrace one another during a vigil honoring Bui, Long and Ebner who were all killed in July

He then went to the roof but realized he was out of ammunition, so he returned to his car.

As Ivanov was loading the magazine, he said he intended to return to the house to kill more people but left instead.

Public records show the house where the party took place is owned by fisherman Karl Bratvold and his wife Vicki. Their soccer star son Tristan, 19, threw the party.

Jansen Garside, who had been friends with Long since the fourth grade, told MailOnline in July that Tristan's parties were laid-back and typically aren't closed.

'They would've welcomed every friend,' said Garside, including Ivanov.

Now Isanov, who classmates described as 'brilliant' and sure to have a bright future, will be behind bars for the remainder of his life.

The rifle was so new that he had to read its instruction manual to operate it as he sat in his car outside the house party.

As Ivanov was hiding in his car outside the house, a male partygoer discovered him.

Ivanov told police he shot the person because he scared him.

Mukilteo Police Detective John Ernst said Ivanov 'stated at that point that it was too late to turn back, and once he had pulled the trigger his adrenaline kicked in'.

Ivanov then went inside the house and shot Bui twice, according to court documents.