Officials said the incident started when deputies were called to a home on the 14000 block of East Plantana Drive in La Mirada for reports of a man with a handgun.
Investigators said Derek Martin went to the home to look for his girlfriend. He instead found a 22-year-old man. He allegedly pointed the gun toward the man and asked where the girlfriend was.
Martin's girlfriend came out after hearing the commotion. Martin told her to get into the car, and she complied out of fear, according to deputies. Martin then took off. The two were eventually located in Brea.
The woman was not hurt. Martin was arrested for assault with a deadly weapon and kidnapping. His bail was set at $100,000.
Anyone with additional information on the case was asked to contact detectives at (562) 863-8711.
