Two years after three men were killed in Federal Way in a 48-hour span, police announced they have solved those murders and another that occurred a month earlier.

At a press conference Tuesday, Federal Way Police Chief Andy Hwang said investigators are recommending the King County Prosecuting Attorney’s office file charges against three young men in the 2016 cases.

The primary suspect in all four murders has been identified as Justice Henderson, of Auburn, who was 17 at the time of the killings.

Those killed were:

• Jeffrey McLaren Jr., 19, who was found deceased at the Cove Apartments parking lot, 33100 block of First Avenue South, on April 3, 2016. He had been shot multiple times.

• Alex Kelley, 26, who was found deceased at the Arcadia Apartments complex, 1300 block of Southwest Campus Drive, at 1 a.m. May 9, 2016. He had been shot.

• Frank Cohens Jr., 27, who was found slumped over the wheel of a parked vehicle, in the 2200 block of South 333rd St., at 10:30 p.m. May 9, 2016. He had been shot multiple times.

• Adam Gutierrez, 30, who was found deceased lying on the sidewalk in the 1800 block of Southwest 356th Street at 11:12 p.m. May 10, 2016. He had been shot multiple times.

Investigators are recommending Henderson be charged with four counts of first-degree murder and two counts of first-degree robbery.

One count of first-degree murder and one count first-degree robbery charges are also recommended against Marchae Garrison, then 17, of Federal Way, in the death of McLaren. Investigators are asking the same charges be filed against Kamajah “K.J.” Skannal, then 20, of Milton, in Cohens’ death.

On July 11, 2016, Henderson was taken into custody by the United States Marshals Service for an attempted murder in Pierce County on May 4, 2016. Henderson was subsequently convicted and is serving a 12-year sentence for that crime.

Henderson and Garrison are in custody of the state Department of Corrections, and Skannal is in King County Jail, Hwang said.

Around the time Henderson was arrested for the attempted murder, he was identified as a potential suspect in the Federal Way murders, Hwang said.

“Because Henderson was in custody and not a threat to society, we held off disclosing his identity or charging him with Federal Way’s homicide cases at that time,” Hwang said. “That gave us the strategic advantage of thoroughly and completely investigating our four cases before revealing the perpetrator and his accomplices.”

The investigation took nearly two years, Hwang said.

“We interviewed hundreds and hundreds of people. … We went through volumes of telephone records, social media records,” Hwang said. “There was a tremendous amount of work that took place to build the case up to where it is today.”

The motive in Cohens’ case was robbery, but the other three killings were random, Hwang said.

“One individual, Mr. Henderson, went on a killing spree,” Hwang said. “… I really can’t put a motive on why Henderson would do that. … He simply lost his moral compass, and he just started killing people.”

All three suspects in the case had ties to a small gang on Federal Way’s westside called MTB, Hwang said.

“They were committing violent crimes,” he said. “Some of these gang members are incarcerated, (some) have been arrested and released, some of them have moved out of the area. What I can tell you is that the Federal Way Police Department has dismantled this group, and it is much quieter on the westside.”

Federal Way Mayor Jim Ferrell said the four homicides rocked the city.

“In the days following these homicides, 500 residents came into these chambers and this City Hall to talk about how they felt about these homicides and how these crimes affected this community,” Ferrell said during the press conference. “This community really came together, and I want to say thank you so much for this community for how they responded.”

Hwang said the department’s hearts and prayers go out to the victims’ families.

“It is impossible to comprehend how senseless it was for these three people responsible for these brutal crimes taking the lives of four innocent people in our community. These tragedies impacted everyone,” Hwang said. “With the arrests and filing charges, it is our hope that we begin some level of closure for the victims’ families and restore and enhance our sense of safety and security in our community.”

Lisa Wollum, McLaren’s aunt, said the arrests and pending charges are a relief.

“It was totally random,” Wollum said. “I think that for the victims’ families that’s the hardest. There isn’t anything that anyone did that would have preceded this. There wasn’t a confrontation. There was just nothing. You are going through your life and the next thing you know your loved one is gone. It is extremely painful, and I think all along we have said we want justice for Jeffery, not realizing that all of these were connected.”

Wollum said there isn’t a day that goes by that she doesn’t think about her nephew, whom she described as a “happy spirit.”

“It is sad to see that taken away at 19 because you just don’t know where they could have gone from there,” she said, referring to her nephew’s age when he died.

The Federal Way Police Department was assisted in the investigation by the Washington State Patrol Crime Laboratory Division; the King County Regional Automated Fingerprint Identification System (AFIS); the Drug Enforcement Administration’s High Intensity Drug Trafficking Areas program; the United States Marshals Service; the Federal Bureau of Investigation; and the Bureau of Alcohol, Tobacco, Firearms and Explosives.