In the mean time I got a call from the police dept saying that my tenant is being investigated for selling drugs and weapons and my cooperation would be helpful.

Our righteous indignation might give us a high of sorts but it does little toward achieving the goal.

The LIBERAL police got hold of this and now use it as a political weapon, demonizing real estate investors as taking advantage of poor people. 

I just had a tenant last week refuse me to show the house for sale because he has weapons in the house, blah blah blah...The idea of the fee for refusing to show is a good idea, plus trying to work with them on maybe an open house once a week from x to x for 2 hours.

When I knew him, he had many weapons, such as a shot gun, sniper rifle, crossbow and hunting knives.

Assault with a deadly weapon, shooting on an occupied dwelling, etc.Stolen license plates and burglarized homes happens in every neighborhood.

Moral outrage and righteous indignation is wasted time and energy.

The Lessor shall not lease or sell the units within fifty (50) feet of Lessee's demising wall to the following users(s): a) Bars, taverns, billiard halls; b) Pawn shops; c) Dance studios or Karate studios; d) Beer or wine-making stores; e) Psychological counseling offices/facilities; f) Unemployment or Social Security offices; g) Liquor stores; h) Tattoo shops/body art/piercing tenants; i) Beauty/Hair Salons, Cosmetology Services, or Nail Salons; j) Gun and Weapon shops; k) Smoke/Tobacco or Vapor/E-Cigarette shops; l) Child Care/Children's gymnasium; m) Dry Cleaning Plant facility; n) Veterinarian/Dog Grooming/Animal Boarding; o) Gym/Workout facility; p) Same day cash/loan shops; q) Massage parlors (except for national chains such as Massage Envy and the like); r) Police substations; s) Military recruiting offices; ort) Any other non-professional use similar to those listed above.

Was it an aggravated offense with a weapon?

Even Uber requires you to have background checks, not carry weapons, drug & alcohol policy, etc.