SIOUX CITY, Iowa (KCAU) – A Siouxland man was arrested Thursday, accused of waiting hours in his ex-girlfriend’s vehicle in South Sioux City before then using homemade chloroform to make her lose consciousness.

According to court documents, a South Sioux City police detective was investigating a missing person case Thursday after a woman’s vehicle was found with her purse and cell phone inside and the windows rolled down. She was later found and taken to the Sioux City Police Department.

The Woodbury County Sheriff’s Office was dispatched around 6:30 p.m. to interview the woman’s ex-boyfriend, who was a possible suspect in the abduction. The suspect, Zack Smith, 20, of Bronson, went to the Law Enforcement Center to be interviewed.

According to court documents, Smith admitted to hiding in the woman’s car for more than three hours to kidnap her. After dropping off someone, he sprang up and displayed an AirSoft pistol. After driving around South Sioux City, he then forced the victim into his vehicle and crossed into Iowa.

Smith then used a blindfold, duct tape, and zip ties to restrict the victim, documents said. He also admitted to having the victim breathing in a homemade chloroform. The woman lost consciousness and woke up in a building that she recognized as a shed on the Smith’s property. She said she alone with duct tape on her ankles and ropes around her wrists. After being able to escape, she was found by family who were searching for her in rural Woodbury County.

Documents said Smith admitted to planning the kidnapping for about two-and-a-half weeks. In a backpack belonging to Smith, authorities found rope, zip ties, duct tape, condoms, and lubrication. Smith allegedly said he used the backpack during the kidnapping.

Smith was arrested and charged with the class C felonies of third-degree kidnapping, assault with intent to commit sexual abuse, and assault while participating in a felony. He was also charged with false imprisonment, a serious misdemeanor. He was booked into the Woodbury County Jail on a $250,000 bond.

Smith was out on bond for the false imprisonment the same victim and another woman in May. Court documents said he sent an email from someone else’s account saying she could pick up her things at his apartment. When she arrived with another person, Smith allegedly locked them in and refused to let them go.