OAKLAND -- Federal criminal investigator Sandra Coke was likely killed during a 38-minute time frame on Aug. 4 at a West Oakland motel by her former lover, who then drove her car to Vacaville and dumped her body in a dry creek bed, according to authorities and court documents filed Friday.
Randy Alana, who has 17 prior felony convictions, was charged with Coke's murder on Friday and faces life in prison without the possibility of parole if he's convicted of killing the 50-year-old woman.
Alana is also charged with one count of vehicle theft and two counts of grand theft on suspicion of taking Coke's Mini Cooper and using her bank card to withdraw more than $400 the morning after she disappeared. He was arraigned on the charges Friday and will be back in court Monday after he is assigned a public defender or hires an attorney.
According to court documents, Alana called Coke on her work cellphone at 8:22 p.m. Aug. 4. Soon after, Coke left her North Oakland home, telling her daughter she was going to see about her missing dog and to pick up a prescription, according to police and court documents.
Video and a GPS ankle monitor attached to Alana showed him "stationary for 38 minutes" at the Nights Inn Motel at 874 W. MacArthur Blvd. At 9:21 p.m., video shows him driving north on Market Street. A short time later, Coke's work cellphone was found about a mile from the motel.
At 9:23 p.m. the GPS tracks stopped; Alana later admitted that he had removed his ankle monitor.
Authorities did not mention any physical evidence directly linking Alana to Coke's murder in their court filings. According to the documents, the case appears to be based on circumstantial evidence, laying out a detailed police account of Alana's actions on the night of Aug. 4 and throughout Aug. 5.
The court documents show that on Aug. 4, from 10:14 p.m. to 10:58 p.m., Coke's personal cellphone was activated in Crockett, Vallejo and Vacaville. A few minutes later, video showing the rear and front of a car matching Coke's vehicle was captured at Rivera and Cherry Glen roads, off the eastbound Interstate 80 exit at Pena Adobe Road in Vacaville.
A Contra Costa County search team would find Coke's body in a dry creekbed a short distance away on Aug. 9. Authorities maintain that after dumping the body, Alana headed back to the East Bay.
Coke's cellphone activated in Pinole shortly after midnight Aug. 5. Minutes later, video shows Alana driving Coke's car into the parking lot of a 7-Eleven store in San Pablo. Video and bank records show Alana withdrawing more than $400 using Coke's debit card from that same 7-Eleven. Coke is not seen on the video.
About seven hours later, Alana drove Coke's car to a Chevron station on 98th Avenue in East Oakland and tried to pull money from an ATM using her debit card, according to court documents, but the card was refused.
Coke's car was found by the Oakland Housing Authority in the 800 block of 32nd Street that evening. Inside the car, authorities found her purse and her federal identification.
Alana was arrested Aug. 6 at the Pittsburg/Bay Point BART station, reportedly while carrying Coke's car keys and debit card. One day later, officials began searching various locations in Solano County. Her body was found on Aug. 9.
Officials have not said how Coke died, but the murder charge does not include enhancements for the use of a gun or a knife.
"Sandra Coke's murder is an unfathomable tragedy that has devastated her family, friends and co-workers," Alameda County District Attorney Nancy O'Malley said in a statement Friday. "I wish to commend the excellent investigative work of the Oakland Police Department in solving this case.
"I can assure that community as well as the family and loved ones of Ms. Coke that Randy Alana will be brought to justice for this brutal and senseless crime."
Coke's younger sister, Tanya Coke, did not return multiple calls and emails for comment.
Alana and Coke met and began a relationship while Coke investigated a capital murder case about 20 years ago.
Before her death, Coke worked as an inspector with the Sacramento branch of the federal public defender's office. The two rekindled their romance sometime after he was paroled from a 15-year bank robbery sentence in June 2012.
Before he was charged in Coke's murder, Alana spent decades in and out of jail. He is considered a high-risk sex offender, according to a state-run sex offender registry, which lists undated convictions for two counts of rape, kidnapping with intent to commit a sex offense and oral copulation.
In 1983, Alana was charged with the beating death of Marilyn Pigott, 23, a woman he had known since elementary school. Alana was eventually acquitted.
While in custody awaiting trial for Pigott's slaying, Alana and a fellow inmate were accused of fatally stabbing 40-year-old Al Ingram. Alana pleaded no contest to the killing in March 1988 and received a six-year prison sentence.
During a jailhouse interview with Bay Area News Group shortly after Coke's body was found, Alana denied harming her but refused to say what happened on the night of Aug. 4. He said the couple had plans to marry.