According to an Instagram post from Baldwin Park Police Department, detectives found 1,800 stolen converters, worth an estimated $500,000, at a business in Norwalk earlier this week.
It came after Baldwin Park police launched the investigation last July due a rise in catalytic converter thefts. Investigators eventually identified a location in South Los Angeles where stolen converters were allegedly being purchased, and another location in Norwalk that was being used as a storage site.
On Tuesday, law enforcement carried out an operation at the Norwalk location. Four people were arrested for selling and purchasing suspected stolen catalytic converters, police said.
During the operation, one man fled the scene and left behind a juvenile. That suspect remains outstanding.
In addition to the 1,800 converters that were recovered, four cars were also seized as evidence, police said.
Replacing a stolen converter can cost up to $2,000.