Man accused of killing transgender teen girl after 'hookup meeting': Police The 17-year-old was reported missing in June. Her remains were found this month.

A 25-year-old man has been arrested for the murder of transgender teenage girl whom he allegedly attacked after a "hookup meeting," said police in Vancouver, Washington.

Nikki Kuhnhausen, 17, was last seen alive on June 6 when she left the house with a man she had reportedly met the night before, according to Vancouver police Lt. Tom Ryan. Her mother reported her missing in June, Ryan said.

David Bogdanov -- a 25-year-old who was arrested Tuesday for second-degree murder -- spoke to police and confirmed he did pick the 17-year-old up, said Ryan.

"David and Nikki went to a residence in the county, and at this time David says Nikki told him that she was biologically male," Ryan said at a press conference. "Bogdanov gave a statement [to police] that that [comment from Kuhnhausen] made him really, really uncomfortable and disturbed him. And he asked Nikki to get out of his van and she walked away."

Bogdanov told authorities he never saw Kuhnhausen after that, said Ryan. However, police determined Bogdanov gave inconsistent statements, Ryan said.

The break in the case came on Dec. 7 when a citizen found a human skull, Ryan said, and remains were uncovered that were confirmed to belong to Kuhnhausen.

When contacted by police on Tuesday, Bogdanov "declined to give any further statements" and was arrested for second-degree murder, Ryan said.

Police believe the suspect and victim "had a kind-of hookup meeting," authorities said, and the alleged attack "arose probably from the hookup meeting."

The suspect allegedly was not "targeting Nikki for a particular reason," authorities added, and prosecutors will determine if the case will be tried as a hate crime.

No information indicates the crime was premeditated, officials said, and there's also no indication the teen and suspect had known each other prior to meeting in June.

Defense attorney Erin Bradley McAleer told ABC News that Bogdanov plans to plead not guilty.

During Wednesday's first court appearance, the state's request for no bail was granted, according to The Columbian.

Bogdanov returns to court on Jan. 2, his attorney said.

At least 22 transgender people -- 19 of them trans women of color -- have been killed in 2019 alone, according to the Human Rights Campaign, an advocacy group. At least 29 transgender people were killed in 2017, making it the deadliest year on record, and at least 26 transgender people were killed in the U.S. in 2018, the group said.

ABC News' Karma Allen contributed to this report.