The plaintiffs say the "shelter has a duty to help, not harm, homeless dogs and cats."
The Animal Legal Defense Fund along with three people from Stockton filed the lawsuit against the City of Stockton.
The suit is not asking for money, only that the animal shelter follow the law.
The shelter is required to hold strays for at least 6 days before euthanization.
But Animal Legal Defense Fund Attorney Jenni James says the shelter's records show a different story over a one year period.
"Early euthansias are happening, 1,500 animals were euthanized before the expiration of the Stockton shelter's minimum holding period," says James.
James says 80 percent of the animals are behind locked doors where the public never sees them.
"Only about 20 percent of the animals are truly being given a meaningful chance of adoption," says James.
The City of Stockton is not commenting on the lawsuit.
Tubbs was voted in last year with 70 percent of the vote and, at 26, became the youngest elected mayor of a larger U.S. city. He is also Stockton’s first black mayor.
Stockton Police are offering a $10,000 reward leading to the arrest and conviction of a 14-year-old boy for murder.
Stockton Mayor Michael Tubbs announced a $20 million donation for financial help for college students.
Stockton and the Central Valley were chosen as the first area for a multi-million dollar investment to create new higher paying jobs.
Every year, thousands of people die because they take their medication incorrectly or forget to take it at all. Tech companies think pill- producing robots and 'smart' prescription bottles could hold the answer.