The man accused of killing Morgan Hill teenager Sierra LaMar made a brief court appearance Wednesday morning and was formally arraigned on charges that he tried to kidnap and carjack three different women in 2009.

Antolin Garcia Torres, now 21, was 17 at the time of the alleged kidnappings, but a juvenile court judge has granted the Santa Clara County District Attorney's Office permission to charge him as an adult in those cases. Prosecutors filed the additional charges last month.

Garcia Torres, who was in handcuffs during his five-minute appearance Wednesday, did not enter a plea to three felony counts of attempted kidnapping. Garcia Torres has not entered a plea yet on a charge that he murdered Sierra, who vanished March 16 on her way to a rural bus stop south of Bailey Road around the corner from her home in unincorporated Morgan Hill.

Her body has not been found.

Authorities learned of Garcia Torres' possible connection to the previous incidents dating back to 2009 while investigating Sierra's disappearance.

Two of the incidents took place on March 19, 2009, one of which involved a stun gun, sources said. The other incident occurred a few days later, on March 26, 2009. Investigators previously said they were looking into whether Garcia Torres -- who once worked at Safeway -- was behind attacks at Safeway stores in the Morgan Hill area in March 2009.

One attack occurred about 8:40 p.m. at the Safeway at 840 E. Dunne Ave. An 18-year-old Gilroy woman told police that soon after she parked behind the store, a man slipped into the back seat of her car. At that moment, she was retrieving a pocket knife from the glove compartment because she was aware of other attacks.

The man grabbed her right hand and opened the folding blade with his thumb. He forced her hand toward her throat and placed the blade on her neck. He didn't speak, but hit her on the leg and "made grunting noises," the police report states. She screamed, startling the man, police said. He jumped out of the car and ran away.

In a separate incident, a 46-year-old San Martin woman was attacked while walking to her car about 11:30 p.m. at the Safeway at Tennant Station.

A man who apparently had entered her car through an unlocked door attacked her, hitting her with his fist and using a stun gun on her head and neck -- but he said nothing. He did not demand anything and fled when a passer-by pulled up and heard the woman screaming.

Earlier that same evening, a 36-year-old Morgan Hill woman was leaving the Dunne Avenue Safeway when she noticed a man walking behind her. As she walked faster, the man also sped up, she told police. After she got into her car and locked the door, the man tried to open the driver's side door. He did not say anything, and the woman drove away.

Garcia Torres' DNA was discovered on Sierra's clothes that were found discarded in a field not far from the bus stop. Sierra's DNA was found in the suspect's red Volkswagen Jetta. He was arrested in May.

Contact Mark Gomez at 408-920-5869. Follow him on Twitter @MarkMgomez