A 22-year-old man who stabbed to death another man along a North Portland street and then months later tried to kill a witness was sentenced Monday to 17 years in prison.

Sioeli Pangia Mohulamu was 19 when he killed Gerrardo Granados-Marin, 33, by stabbing him repeatedly in the back and arms on Oct. 5, 2015. The crime happened along the 5500 block of North Columbia Court, a street lined with rundown cars, vans and at least one camper.

Granados-Marin walked about 100 yards before collapsing outside a home next to a fence, and the residents called 911, investigators say.

It’s unclear how Mohulamu and Granados-Marin knew each other or why Mohulamu attacked Granados-Marin.

But Granados-Marin had methamphetamine and alcohol in his system at the time of his death. It’s not known if Mohulamu was intoxicated, but his defense attorney said his client's behavior deteriorates when he drinks alcohol.

Witnesses said Granados-Marin and another man had been smoking meth in a parked camper. Police originally arrested that other man -- Leo Burns -- in the killing because witnesses said Burns and Granados-Marin had gotten into a fistfight earlier that night. Investigators said Burns had lied about being in the fight.

But authorities released Burns 10 months later when prosecutors determined he didn’t kill Granados-Marin.

Meanwhile, Mohulamu was talking about how he’d killed Granados-Marin to at least one other person, according to the prosecution.

Then in July 2016, he stabbed a man in the neck while visiting a North Portland house because he worried that the man was going to cooperate with police in building a murder case against him, said Deputy District Attorney Todd Jackson.

Last month, Mohulamu pleaded guilty to first-degree manslaughter for killing Granados-Marin and attempted aggravated murder of the potential witness.

On Monday, Mohulamu declined to make any statements during the hearing in Multnomah County Circuit Court. His defense attorney, Jon Martz, said both stabbings were "snap" decisions or "bad judgment" by his client.

Mohulamu had previously been convicted of third-degree robbery and possession of methamphetamine. In an unrelated incident, he also was shot in the back five months after the killing of Granados-Marin for reasons that are unclear.

-- Aimee Green