Image copyright Wilsonville Police Image caption Police in Wilsonville, Oregon tweeted this picture of David Michael Kalac after his arrest

A US man accused of murdering his girlfriend and posting grisly pictures of her body online has been arrested.

David Michael Kalac, 33, had warned he was hoping the authorities would find and kill him.

But police in Wilsonville, Oregon, tweeted that he was detained "without incident".

The body of Mr Kalac's girlfriend, Amber Lynn Coplin, was discovered by her 13-year-old son at their home in Washington state on Tuesday.

After the killing, the authorities began receiving tips about graphic images of a woman's body posted on the online forum 4chan.

The person who posted the pictures, which police said "in all likelihood" was Mr Kalac, described how the victim was killed.

Mr Kalac, driving the dead woman's car, was briefly involved in a high-speed chase with police before evading capture. But he was later arrested in Wilsonville, about 20 miles (32km) south-west of Portland.

Police said Mr Kalac had a long history of violent crime in Washington state and Virginia.

He has been charged with second-degree murder.

4chan has gained notoriety as one of the most anarchic corners of the internet. Earlier this year hundreds of nude photos of celebrities were posted on the site.