The district attorney is expected to wait for the completion of local and federal investigations before any formal filing decision.
"While charges will not be filed at this time, the arrest of Jose Alejandro Sanchez Ramirez by the Oxnard Police Department was clearly appropriate and lawful," the district attorney's office released in a statement.
Jose Alejandro Sanchez Ramirez, 55, will be able to return home to Yuma, Arizona, but will return on May 4 to talk to investigators.
"My father and the rest of my family are praying for everyone's speedy recovery. Our concern and thoughts are with the victims of the accident," Ramirez's son Daniel Sanchez said.
On Tuesday, Ramirez's truck, which was pulling a trailer, was stopped on the tracks, causing a Metrolink commuter train to crash into the vehicle and derail. Dozens of people were injured, but no one was killed.
The National Transportation Safety Board revealed preliminary information from their investigation during a press conference Thursday afternoon.
Based on data recorder on the train, the horn sounded off 12 seconds before impact, the throttle was moved to idle 11 seconds before impact and the emergency brake was pulled eight seconds before impact. At the time of collision, the train was going about 56 mph, said Robert Sumwalt with NTSB.
Sumwalt noted these numbers may change slightly when the final investigation is released.
Based on camera footage, all signals were working properly. As the train was approached the crossing, the truck's headlights and emergency flashers were on and the driver's door was open, Sumwalt said.
The truck appeared to be straddling the rail and facing the train at an angle, but the trailer did not appear to be straddling the rail at all, Sumwalt said. Only the trailer was engulfed in flames after the crash.
Ramirez's lawyer Ron Bamieh has previously said his client accidentally drove onto the tracks and became stuck. Ramirez allegedly continued forward in an attempt to get enough speed to get his wide pickup over the rails and tried to push the truck, but wasn't able to and fled before impact.
Ramirez was scheduled to be in the Oxnard area for six weeks to service farm equipment. Ramirez's son told investigators that his father was not familiar to the area.
In the coming weeks, investigators plan to obtain cell phone records to see if Ramirez was using an electronic mapping device.
The full investigation is expected to take several months to complete.