The body of a woman found near a Northern California park last week was identified today as a missing federal investigator, according to authorities.

An autopsy completed by the Alameda County Coroner's office confirmed the body as Sandra Coke, 50, Oakland police spokeswoman Officer Johnna Watson said during a news conference.

Watson declined to discuss Coke's cause of death.

The federal investigator, who lived in Oakland, was reported missing by her family on Aug. 4 after following a tip on her stolen dog.

Earlier, registered sex offender Randy Alana, 56, was identified as a person of interest in Coke's disappearance.

Investigators believe Alana and Coke were together the night she went missing, according to the Oakland Police Department.

READ MORE: Missing Oakland Investigator's Friend Fears 'Something Has Happened'

Alana is registered as a high-risk sex offender with a criminal history that includes kidnapping and rape, according to the state's database.

He and Coke dated more than 20 years ago, Coke's friend Dan Abrahamson told ABC San Francisco affiliate KGO-TV.

"He reappeared in the Bay Area rather recently and reached out to Sandra for help," Abrahamson told KGO-TV.

Alana was taken into custody on an unspecified parole violation Tuesday and is being held in the Santa Rita Jail in Dublin, Calif., without bail, according to Alameda County online records. He is scheduled to be arraigned in Alameda County Superior Court on Aug. 16.

Coke was last seen at her home Sunday by her 15-year-old daughter. A spokesperson for the family said she left the house to follow up on a lead related to her missing dog.

"There's no question something had happened. There's no way she would have ever left her daughter there alone," Wendy Springer, Sandra's best friend, told ABC News.

For weeks, Coke had been looking for her beloved dog, Ginny, who disappeared after someone broke into her home in May. Coke offered a $1,000 reward on "missing" posters. Tips were called in, but they all were dead ends.

Then Coke discovered a new lead in finding Ginny.

"She told her daughter that someone called about the dog," her sister Tanya Coke said.

READ: Oakland Woman Vanishes While Checking Tip on Her Stolen Dog

Coke's family said she left the house to meet the caller, hoping to be gone for a half hour, but never returned. Coke's daughter then tracked her mom's work and personal iPhones using a GPS application. Both had apparently been dumped: one on a Richmond, Calif., Highway, the other near Oakland, Calif.

"The phones were still working the next morning, sending a signal," Tanya Coke said.

Police found Coke's Mini Cooper two miles from her home.

"It's absolutely heartwrenching," Tanya Coke said last week. "Every parent, every sibling's nightmare. It's especially upsetting that she might be in danger and that there is foul play here."

ABC News' Gio Benitez and Josh Haskell contributed to this report.