Suspect in Yakima, Washington, triple killing fatally shot himself after calling his mom, police say

The suspect in a shooting that left three people dead in Washington state killed himself hours later after he borrowed a stranger's phone, called his mom and made "incriminating statements, including, 'I killed those people,'" the Yakima police chief said Tuesday.

The suspect had "a large amount of ammunition" and a semi-automatic handgun at the scene where officers found him, Chief Matt Murray said in a Tuesday evening news conference, adding the motive is under investigation.

CNN's Paul P. Murphy contributed to this report.