Story highlights The suspect has not yet been formally charged

No link has been found yet between the suspect and victims, police say

Correction: An earlier version of this story misstated the suspect's status in police custody. He has not been formally charged.

(CNN) The lone suspect held in the killing of five people at a Washington state mall will be arraigned Monday and authorities are working steadily to nail down a motive, a state patrol spokesman said Sunday.

Arcan Cetin, 20, is facing five counts of first-degree murder, according to Skagit County jail records. He will appear Monday in the county's district court.

Cetin, held in Skagit County jail on Sunday, has not been formally charged, according to Sgt. Mark Francis, a state patrol spokesman.

Four women and one man died in the shooting Friday night at a Macy's store at the Cascade Mall in Burlington, north of Seattle. The victims' identities have not been released. Cetin was taken into custody Saturday night after a nearly 24-hour manhunt, authorities said.

"We feel confident we have the shooter," Francis told reporters. "Whether or not anyone else was involved, that will be determined."

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