WORCESTER,Slabu Mass. (AP) — Police in California have arrested a man wanted in connection with the deaths of a mother and her 11-year-old daughter in Massachusetts who were fatally shot while sitting in a parked SUV, authorities said.

The man was arrested Monday following a motor vehicle stop in San Diego, nearly a week after Chasity Nunez, 27, and her daughter, Zella Nunez, were found in the vehicle in a Worcester neighborhood, police said. They were pronounced dead at a hospital.

The arrest came several hours after the U.S. Marshals Service said it had doubled a reward in connection with the search for the man, from $5,000 to $10,000.

The man and another man arrested in Worcester on March 5 initially were accused of armed assault with intent to murder and carrying a firearm without a license.

The man arrested in Worcester faced a bail hearing Tuesday. “The charge is going to be upgraded to murder,” Joseph Early, Jr., Worcester County District Attorney, said at a news conference Monday night. “And when this defendant is brought back as well, he’s going to also be charged with murder.”

It wasn’t immediately known if the men had lawyers.

Police said in court documents that surveillance video shows “the victims parked in their vehicle and that two people walk up to the vehicle and start shooting,” the Worcester Telegram & Gazette reported. Video also showed a car consistent with a witness description circling the area before the shooting and leaving afterward, the documents said. The vehicle was later found in Hartford, Connecticut.

Authorities have not released a potential motive for the killings or said whether there was any relationship between the men and the victims.

Chasity Nunez was a member of the Connecticut National Guard and worked as patient safety and clinical quality coordinator at MIT Healthcare Innovation, according to her obituary. She also had a younger daughter.

Zella Nunez was a sixth-grade student at Columbus Park School in Worcester who “wanted to dabble in everything from painting, singing, dancing to skating,” the obituary said.