Eyewitness News first reported Friday morning that police had arrested the suspect. Three other people who were detained Thursday have since been released.
Los Angeles Superior Court records show Harris has a criminal record, previously charged with possession of a firearm; person in possession of a concealed weapon; possession of a loaded firearm in a vehicle; robbery; attempted robbery; and burglary.
The Salinas brothers, Robert and Tony, own United States Fire Protection in the 8700 block of Cleta Street, where workers Josimar Rojas of Downey and Irene Cardenas of Cudahy were fatally shot Wednesday.
According to a spokesperson for the business, when Tony Salinas' wife, Susana Perez-Ruelas, and her 13-year-old son arrived at the shop, the suspect forced them to go to the family's home down the street. The boy handed over the car keys and the suspect held a gun to the boy's head. According to the shop's spokesperson, the gunman then shot and killed Perez-Ruelas when she tried to defend her son. The suspect shot the boy in the arm, and also shot Maria Fuentes, Tony Salinas' mother, in the face.
The 13-year-old has been released from the hospital. Fuentes remained in the intensive care unit Friday night.
The family's attorney told the public that the shootings were not the result of illegal activity.
"The Salinas family is not involved in any illegal activities," said Arshak Bartoumian, attorney for the victims' family. "This has been reported as one possible theory for these killings. This theory was placed in the public by various sources without any facts. The Salinas family is a hard-working family. They have tried to live the American dream by running a prosperous business. Unfortunately, they were involved in the senseless killings of three people."
A friend close to the family said money was tight and one of the family members was brokering a deal to sell a 2010 Camaro on Craigslist for $25,000. The friend also said the gunman showed up regarding the vehicle before shots were fired.
A source close to the family says that selling the Camaro was an effort to save the family's home. It is listed in foreclosure but according to the family's attorney, they believed that they would be able to hold on to the property.
"Like most homes in California, due to the market being down, it was under water," said Bartoumian. "The family has been consistently working with the bank in trying to get a loan modification."
The family also sent out their thanks Friday for the support of the community.
"The family would like to thank the community in supporting them, and the authorities that have been involved, working endlessly with their dedication in this investigation to find the killer."
The motive for the shooting is still unclear, but police say the victims were targeted.
Anyone with information related to the case is urged to call the Downey Police Department at (562) 904-2340.
Harris was being held on $1 million bail Friday. He is expected in court Monday.
