Registered sex offender charged after alleged Tiburon bike-path attack

Tiburon police arrested a registered sex offender about five hours after his release from jail last week, saying he grabbed a woman on a bike path late June 24 and tried to drag her into nearby bushes before she fought him off.

Robiel Teklu Sium, 29, was booked into Marin County Jail early June 25 and charged with a felony count of false imprisonment and a misdemeanor count of sexual battery, court records show. Tiburon Detective Sgt. Rob Law said the department is seeking additional charges.

At Sium’s arraignment June 26, his attorney asked for more time to enter a plea while she reviews police reports. Marin County Superior Court Judge Kevin Murphy set a new hearing for July 2 and ordered Sium held in jail without bail.

According to Law, the woman reported being attacked about 10:25 p.m. on the Old Rail Trail, near the Belvedere Tennis Club. A man approached her, spoke with her briefly, then allegedly grabbed her breasts and tried to force her into nearby bushes. She fought him off and ran toward Blackie’s Pasture, Law said.

Officers searched the area and found a man who fit the woman’s description on the patio of Woodlands Market at The Boardwalk Shopping Center. They stopped him, and the woman identified him after officers took her to the market, Law said.

Just hours before the Tiburon attack, Sium had been released from jail in a separate case: his June 18 arrest in San Rafael, where police said he climbed a fence to get into a fitness studio on Grand Avenue, tried to "make physical contact" with people exercising and refused to leave. He was booked on suspicion of burglary and assault with intent to commit rape.

Sium was on parole for a 2023 sexual battery conviction, which required him to register as a sex offender. Marin Chief Deputy District Attorney Geoff Iida said that rather than file criminal charges in the San Rafael case, his office on June 22 filed a petition to revoke Sium's parole, and the California Division of Adult Parole Operations placed a no-bail hold on him. Sium was arraigned on that petition June 23. However, on June 24, state parole officials dropped the no-bail hold and released Sium from custody without notifying the District Attorney's Office, Iida said.

Tiburon police said anyone with information or who has had a similar encounter can call the department at 415-789-2801.

This story was updated after the June 26 arraignment hearing.