The arrest comes a day after Orange County sheriff's investigators recovered the car of one of the victims, 49-year-old Elizabeth Palmer.
Palmer's body was discovered inside Golden Sun Sales office in Stanton, a business that sells manufactured homes. She worked there for years as a secretary.
Matthew Francis Scott, a 42-year-old salesman, was also found fatally shot in the office. Their bodies were discovered by Scott's father.
Investigators had been looking for Palmer's 2004 Lexus GS300 since the killings. Detectives located the vehicle this past Sunday in a back parking lot of the El Dorado Inn in Anaheim.
Authorities say the car is in good condition, the ignition is not punched. The license plates were replaced with paper ones from South Bay Toyota.
After the car was recovered, the forensics lab took a closer look inside of the vehicle. At this time they are not disclosing what evidence was found. But between the tips they received from the public and the evidence found in the vehicle they were able to apprehend the suspect.
"Forty investigators flooded the area," said Joe Gaul from the Orange County Sheriff's Department. "Ultimately we were given names of subjects to check into and one of them turned out to be our suspect."
"I am just glad that they got this guy because I have been waiting almost 10 months for this," said Richard Palmer, the victim's husband. "This last week has been horrible for me. I am just glad that they caught somebody."
Thomas is in custody now and is facing murder charges. Authorities say they still are not sure if there was a motive. No money was kept at Golden Sun Sales office. Officials have not ruled out the possibility that the two may have been targeted for some unknown reason.
