A teenage relative of a notorious Australian serial killer was sentenced to 43 years in prison Friday for the ax murder of a friend in the same forest where his great-uncle killed seven backpackers.

The judge found Matthew Milat remained a serious potential danger and admired his infamous relative. According to court documents, Milat boasted after the murder: "You know me, you know my family ... I did what they do."

Milat, 19, had pleaded guilty killing David Auchterlonie on the victim's 17th birthday in 2010 in the remote Belanglo State Forest southwest of Sydney.

His great-uncle, Ivan Milat, killed and buried the bodies of seven young backpackers in shallow graves there between 1989 and 1992. He is serving a life sentence.

Acting Justice Jane Mathews ordered the younger Milat to serve at least 30 years of his 43-year sentence. Milat, who was 17 at the time of the killing, was also ordered moved from juvenile to adult prison.

She rejected his claims of remorse and said poems he wrote in prison glorified his crime. "This was a thrill kill," she said, taking the life of an "innocent young man who was unfortunate enough to be his friend."

Court documents said Milat lured his victim with the promise of marijuana and then accused him of spreading rumors that Milat had stolen money.

An accomplice was sentenced to 32 years in prison. Cohen Klein used his cellphone to record the last 15 minutes of Auchterlonie's life, including his pleas for mercy and groans of pain.