"If not for the brave and heroic efforts of Deputy Brown, the lives of other potential victims may have been lost," said Supervisor Don Knabe.
In the dark of the morning on May 6, Brown and his partner heard the distinct cracks of a high-powered rifle in the Hawaiian Gardens neighborhood and moved aggressively toward the home where they originated.
"I was reacting, but I was also scared. The heart gets to pumping? worried about getting shot yourself," said Brown.
Inside the house, five people were shot and six others were scrambling to escape. Two of those who survived were hiding in a bathroom and four others sought cover on the roof.
Investigators say Mercado was on a mission to kill his former girlfriend and anyone else in the home, and intended on burning the house down.
Mercado was allegedly armed with a military-style assault weapon when Deputy Brown spotted him in the dark.
"I saw he had an AK-47, told him to drop it, he turned, faced me and raised his rifle... he was going to fire on me. So I fired two shots, taking the suspect out," said Brown.
In all, three of the shooting victims were killed.
On Tuesday, the L.A. County Board of Supervisors recognized Brown's actions that morning, crediting the deputy with preventing more deaths.
"We want to thank and commend Los Angeles County sheriff's Deputy Freddy Brown for his incredible display of courage, in the face of life-threatening peril to himself, and protecting the residents of Los Angeles County without hesitation," said Knabe. "Freddie, congratulations on a job well done. You are a hero."
The honor seemed difficult for the deputy to swallow, especially when people started referring to him as a hero.
"I was just doing my job," said Brown. "They train me to do something; I get paid to do it; I went down there and did it."