Honolulu police Detective Dru Akagi testified Ivy Harris met U.S. Marine Master Sgt. Nathaniel Cosby during the early morning hours of May 16 outside Kelley O'Neil's pub in Waikiki.
Surveillance video shows them walking away together then entering the Aston Waikiki hotel about ten minutes later.
"She was with a male getting into an elevator," Akagi said.
He testified the man with Harris was Cosby, who was registered in room 924.
Harris, 29, was a prostitute based in Las Vegas.
The 39-year-old Cosby is charged with murder, manslaughter and obstruction of justice.
Akagi says when he questioned Cosby "he could not recall what happened in that hotel room."
But hotel cameras show Cosby leaving alone a couple of hours after he and Harris arrived. He is seen rolling a large duffle bag that he loaded into the back of his rented SUV.
"His explanation for having the bag was that he needed it for gear and he loaded it with about 70 pounds of clothes," Akagi testified.
He said Cosby told him that when he woke up Harris was not in his room. But Akagi told the prosecutor that it would be nearly impossible for her to exit the hotel without being spotted by surveillance cameras.
Her body was found in brush near Yokohama Bay four days after she was last seen alive.
Three witnesses testified that when Cosby reported for duty at the Joint POW/MIA Accounting Command he had a cut on his temple. He told them that he slipped in his hotel room and struck his head on a night stand.
Retired police Detective Phil Camero said that records from cell phone towers showed Cosby's phone pinged a tower close to where Harris's body was found. Prosecutor Maj. Doug Hatch said his theory is that Cosby drove to Yokohama twice - once to scout the location and a second time to dump the body.
An NCIS investigator testified that DNA swabs taken from inside Cosby's duffle bag showed a sample that matched Harris. A fragment of a fake fingernail and strands of hair that could have come from a wig were also recovered. When Harris's body was examined several fake fingernails were broken off her hands.
The Article 32 Hearing before Col. Doug Gardner will determine if Cosby will face a court martial.