Don’t the police arrest on federal laws?
I remember one time where I worked someone was accused of breaking a federal law and they had local law enforcement arrest her at work.
By the way the employer had no basis to have her arrested and the police apologized to her but they had to arrest her since he filed charges and presented evidence that looked legitimate.
She didn’t sue the police she sued the company and won a nice settlement (i think over a quarter million) it’s been 8 years I don’t remember the exact details.
Not usually, except in the case of immigration, Congress has passed laws specifically requiring states to assist the Feds.
Recently a bank was robbed near where I live. The local police arrested the perp because robbing banks is against state law. After he was charged, the Feds got a Federal indictment (the Feds cannot charge out by complaint like locals but must present their case to a grand jury for an indictment) because robbing the bank was also against Federal law. There was no clash of jurisdiction. Typically the states and Feds cooperate in enforcing laws.