Prosecutors on Monday charged the man arrested after a deadly mall shooting with five counts of first-degree premeditated murder and said he confessed to the crime.

Arcan Cetin made his first court appearance since the killings Friday night at a mall in Burlington, Wash., about 60 miles north of Seattle. Prosecutors said Mr. Cetin, 20 years old, walked into a Macy’s department store and gunned down five people. Four women and one man died, ranging in age from 16 to 95.

Mr. Cetin, clad in a loose-fitting blue shirt and red pants, with his hands shackled at the waist, said nothing other than “yes, your honor,” when asked if he understood the charges and if he had time to consult with an attorney.

The judge appointed a public defender to represent him.

Charging documents don’t indicate a motive for the shootings, but they say Mr. Cetin confessed after being questioned by investigators.