Washington police are investigating images posted on 4chan which purportedly show the body of a recent murder victim who was found dead on Tuesday in a flat in Port Orchard, a city 13 miles from Seattle. 

The images show a naked woman lying on a bed with red marks around her neck. They were shared anonymously on the internet forum with the words: "Turns out it’s way harder to strangle someone to death than it looks on the movies". 

When 4chan users questioned whether the photos were genuine, the anon replied: "Check the news for Port Orchard, Washington, in a few hours. Her son will be home from school soon. He'll find her, then call the cops. I just wanted to share the pics before they find me."

Some of the photos posted on 4chan were also tweeted to NBC News station King 5 and several other news agencies. The images appear to have been published on the forum before officers were called to the scene by a family member at 3:30 pm local time. 

Kitsap County Sheriff's Office Deputy Scott Wilson told King 5: "Any time we have images of this graphic nature that are posted online and perpetrate to be this crime scene we are going to take those seriously, but we're unable to confirm whether those photographs are of this victim."

UPDATE: Murder suspect David Kalac has been taken into custody after giving himself up to a police officer. He had been on the run in the victim's car, a gold 2001 Ford Focus.

The 30-year-old victim, who has been named as Amber Coplin, was Kalac's ex-girlfriend. Her body was discovered by her 13-year-old son. When police arrived on the scene, they found the message "she killed me first" on a picture. The words "bad news" were written on the blinds of the flat, and "dead" written on the victim's driving licence, which was found next to her body.

According to police, Kalac walked out to the officer in a vacant parking lot. He was not armed.