SAN JOSE — The father of a brother and sister who were hit and killed by a driver fleeing from a Santa Clara County Sheriff’s deputy has filed a legal claim against the county, alleging the deputy engaged in an improper pursuit that failed to signal the victims to the approaching danger.

Al Nievas, the father of 25-year-old Precious Nievas and 22-year-old Philip Nievas, both of whom died in the April 26 crash, contends that a deputy’s failure to activate his vehicle’s siren contributed to his children’s deaths.

“The loss of my daughter and son has left my life empty and every day is full of ache,” Al Nievas said in a statement to this news organization. “The sheriff (deputy) never used a siren to warn my children that there was an emergency. They had no chance. This never should have happened.”

The sheriff’s office referred an inquiry to the County Counsel’s Office, which declined comment through a county spokesperson. The legal claim, which now must be evaluated by the county, is a procedural requirement that typically precedes a lawsuit.

According to San Jose police, at about 10 p.m. that night, Philip Nievas was driving a 1999 Toyota Camry with his sister as a passenger when, as they turned left from Lawrence Expressway onto Mitty Way, their car was broadsided by a speeding 2017 Honda Accord driven by 19-year-old Roberto Joseph Garcia.

Garcia was charged with two counts of murder, two felony counts of eluding a police officer, two felony weapons charges for a loaded gun reportedly found in his car, and illegally possessing marijuana for sale. He was also charged with driving under the influence of marijuana for an arrest three weeks earlier after he was reportedly seen driving recklessly on Highway 101 near his home city of Morgan Hill.

He is currently being held at the Main Jail in San Jose on $1.5 million bail, according to jail records.

In the wake of the deadly collision, the sheriff’s office denied that Deputy Ryan Vesey had fully engaged in a pursuit of Garcia. The death certificates for the Nievas siblings both cite that they died after being “struck by another automobile that was involved in a pursuit by law enforcement.”

San Jose police, which investigated the crash, reported that the deputy activated his patrol vehicle’s flashing lights to initiate a traffic stop after seeing Garcia’s car make several lane changes then a U-turn without signaling. A police report states that “it is not believed Deputy (Vesey) had time to activate his siren before the crash.”

Nievas’ claim, filed this month by attorney Richard Alexander, disputes the official account and argues that Vesey was negligent by not turning on his vehicle’s siren during a brief high-speed chase on northbound Lawrence Expressway that ended with the deadly collision.

The claim further alleges the sheriff’s office’s pursuit policy is not in line with California Vehicle Code standards, which combined with the deputy’s discretion “further continued a pursuit which should have been terminated due to a high risk of injury to innocent bystanders.”

Alexander said that in response to his legal action, he anticipates the eventual release and review of law enforcement’s video and audio recordings from the night of April 26, with the aim of shedding more light on the incident.

“Right now Al Nievas and the Nievas family is in the dark and they don’t know the details of what happened that night,” he said. “This lawsuit will answer those questions.”