Drive by, see if there's any other evidence of any of this, leave if there isn't - because an unverified phone call alone really shouldn't count as probable cause?
Exactly! Especially since law enforcement has (successfully!) argued that they have no legal duty to serve and protect you.
https://en.wikipedia.org/wiki/Warren_v._District_of_Columbia
https://en.wikipedia.org/wiki/Maksim_Gelman_stabbing_spree#L...
You can't have your cake and eat it too!
If you don't have an obligation to protect, you don't have immunity when you shoot at anyone who is not shooting at you.
IANAL. My understanding is police have a duty to the public at large, not to an individual person outside of a special relationship (i.e. witness protection). If the police did have a duty to individuals, the state would be unable to allocate police resources to best serve the public. Essentially, individual priorities would DDOS police resources. In the case you reference:
> a government and its agents are under no general duty to provide public services, such as police protection, to any particular individual citizen. [...] A publicly maintained police force constitutes a basic governmental service provided to benefit the community at large by promoting public peace, safety and good order. [...] Publicly furnished police protection may accrue to the personal benefit of individual citizens, but at all times the needs and interests of the community at large predominate.