The second person charged in the brutal kidnapping and torture of a man whose body was found stuffed in a suitcase floating in San Francisco Bay was identified by authorities Friday as a 36-year-old woman.

Angel Anderson confessed to Sacramento police that she helped kill 23-year-old George Randall-Saldivar, according to the San Francisco Police Department. She was arrested on suspicion of murder, conspiracy, false imprisonment and kidnapping.

Randall-Saldivar’s body was discovered floating near the east side of Pier 39 along the Embarcadero on Feb. 18. Two days later, the medical examiner determined Randall-Saldivar was a homicide victim and alerted police.

On Feb. 20, Sacramento police contacted San Francisco authorities and said that a person in their custody claimed to have participated in the grisly killing. No information was provided on why Anderson was already in custody.

Investigators determined that the killing of Randall-Saldivar occurred at a home on the 1200 block of Market Street between Feb. 3 and Feb. 5 based on information provided by Anderson, police said.

A registered tenant, Gerald Rowe, 47, was arrested and booked at the San Francisco County Jail on charges of murder, conspiracy, false imprisonment and kidnapping. Rowe pleaded not guilty to the charges Wednesday.

Anderson attempted to clear Rowe of any wrongdoing during her confession, according to court records.

Inside the apartment, police said, officers found video of the killing. The video shows Rowe and Anderson having consensual sex with the victim before Rowe left the room and returned to see Anderson talking with Randall-Saldivar at the front door, according to court records.

Anderson tied Randall-Saldivar’s hands behind his back while he sat in a chair and placed a noose over his neck, according to court records. Rowe sat in another chair and watched, before Anderson placed rope around a stationary object to create a “pulley mechanism.” She then placed the bag over the victim’s head, prosecutors said.

Rowe briefly left the bedroom to get narcotics that officials believe may have been fentanyl, according to court records. Anderson then injected the narcotics into the victim’s arm, and both Anderson and Rowe used the rope to lift Randall-Saldivar. They tugged and pulled the rope while he was suspended in the air, court records said.

Randall-Saldivar was then lowered to the bed, according to court records. The bag was removed from his head and Anderson slapped him across the face. Both Anderson and Rowe then stuffed Randall-Saldivar’s body into a suitcase and left it in the room for about 20 hours, court records said.

The two defendants allegedly disposed of the suitcase in the bay, along with some of their clothing.

Randall-Saldivar’s body was found floating in the bay. The motive for his killing remains unknown.

Anderson, who identifies as a transgender woman, was transported to San Francisco on Wednesday and was booked at the County Jail. Anderson and Rowe are being held without bail.

Sarah Ravani is a San Francisco Chronicle staff writer. Email: sravani@sfchronicle.com Twitter: @SarRavani