D.C. police said they have arrested the former boyfriend of a woman who disappeared eight years ago.

Authorities said Jose Angel Rodriguez-Cruz was arrested Friday and charged with killing 47-year-old Pamela Butler.

Butler, who worked for the Environmental Protection Agency, disappeared from her Northwest Washington home in February 2009.

"It's been like a roller coaster that you just -- a roller coaster ride that you never get off, that never ends," Derrick Butler said.

Butler's body has never been found, but a judge declared her dead last July.

After Butler's disappearance, police questioned Rodriguez-Cruz, whom she had met through on online dating service.

"She was a loving, caring person to me. It was nothing she wouldn't do for me," Thelma Butler said.

Authorities reopened the case in February, but it was not immediately clear what led them to arrest him this week.

Rodriguez-Cruz, a former military police officer, has previously denied any involvement in Butler's disappearance.