As noted by several here there has been many rulings affirming that.
The primary SCOTUS one being Castle Rock vs. Gonzalez.
The government has no duty to protect any individual, and if they fail to do so they are not liable.
They are required to not infringe on your RKBA which allows you to protect yourself though.
Funny how antis would like everyone to believe the opposite of both.
That the government can and will provide protection (which is comforting to believe, someone else will solve your personal protection needs) and that the RKBA is not a right and can be infringed to any extent.
The most telling example that you cannot possibly misinterpret is Warren v. District of Columbia.
Three women were in a home, 2 upstairs when they heard the third being attacked downstairs. They called the police multiple times, who assured them they were on the way multiple times.
About 30 minutes later they though things were okay because they didn't hear screaming anymore, and the two went downstairs.
Turned out they were still there.
"For the next fourteen hours the women were held captive, raped, robbed, beaten, forced to commit sexual acts upon each other, and made to submit to the sexual demands of their attackers.''
The police never arrived.
Court ruled: "...fundamental principle of American law that a government and its agents are under no general duty to provide public services, such as police protection, to any individual citizen".
This is at a time when DC had the handgun ban in place, and firearms had to be stored in an unusable manner. A situation that has been the case from 1976 until Heller in 2008.