After the Dec. 2015 shooting at Inland Regional Center in San Bernardino, Calif., residents in the area began to apply for concealed carry weapons permits en masse. San Bernardino County's applications increased nine-fold. Neighboring Riverside County also saw a drastic increase in their CCW applications.

Since that tragedy almost three years ago, Riverside County has had a very steady flow of applications coming in. So much so that Sheriff Stan Sniff hired more employees to handle the CCW backlog, which sat at a two-year await, as of this past April.

A resident and five pro-gun groups have filed a lawsuit against Riverside County and Sheriff Sniff for his concealed carry license policy and practices that, the plaintiffs allege, are unconstitutional.

Riverside County resident Arie van Nieuwenhuyzen purchased a handgun with the intent of applying for a CCW. When he asked the Sheriff's department how he would go about apply, he was told he was ineligible for a permit because he's a U.S. resident, not a U.S. citizen.

Van Nieuwenhuyzen has lived in Riverside since 1983 as a legal U.S. resident. According to the lawsuit, van Nieuwenhuyzen has been a successful business owner and member of the community. He is an active member of his church and teaches Sunday School. He "has obeyed all laws and customs of his adopted country and state."

“Courts across the country have long held that legal United States residents are entitled to the same constitutional protections as everyone else,” lead attorney George M. Lee said in a statement. “Sheriff Sniff’s discriminatory and unconstitutional policies and practices are denying people access to the right to keep and bear arms and violating the Fourteenth Amendment’s command that all people shall enjoy equal protection of our laws.”

Lee said Sheriff Sniff is impeding on van Nieuwenhuyzen's Second Amendment rights.

“Mr. van Nieuwenhuyzen has a fundamental human right to carry his gun outside his home for self-defense, but Sheriff Sniff’s policies and practices prevent him from doing so. Those customs are our first target in this case, and we look forward to forcing Sheriff Sniff to respect and follow the United States Constitution,” Lee said.

The Calguns Foundation (CGF), Second Amendment Foundation (SAF), Firearms Policy Coalition (FPC), Firearms Policy Foundation (FPF), and Madison Society Foundation (MSF) have signed onto the lawsuit as institutional plaintiffs.