ANTIOCH, Calif. (KRON) – The search continues for the person who shot and killed a 76-year-old woman in Antioch.

Initially, police indicated this was possibly a drive-by shooting, but an altercation may have led to shots being fired.

The Antioch Police Department has not responded to our requests for updates on the homicide investigation launched Tuesday night.

At around 7 p.m. that evening, a 29-year-old man reported a 76-year-old woman in his car was injured in the relatively new and quiet park ridge community.

The woman was pronounced dead at a hospital not long after officers and paramedics found her suffering from at least one gunshot wound in her back near Canada Valley Road and Pinnacle View Way.

Mayor Lamar Thorpe says it may not have been a gang-related drive-by like investigators originally thought.

“This situation could have been a number of things. It could have been road rage. It could have been something else. I don’t know. So, it’s still too early to determine what that’s going to be,” Mayor Thorpe said. 

This marks the city’s fourth homicide of the year – All of them happening in the past two and a half weeks.

This is compared to 12 homicides reported all of last year.

On the first of this month, 34-year-old John Henderson Walton Jr. was arrested for allegedly killing his 30-year-old girlfriend and his 15-year-old son a few days earlier.

Police say both died from blunt force trauma.

Investigators are also still looking for the person who shot and killed a man in a Delta Fair Blvd. parking lot last month.

“The proliferation of weapons makes it more and more difficult for us at the local level to deal and put our arms around these situations,” Mayor Thorpe said. 

While police continue to respond to gun-related emergencies, Mayor Thorpe says the city has applied for state funding to help pay for crime prevention measures.

Last month, the city council also passed a gun storage ordinance.