They were instructed to arrest the person who was breaking the law.
"But the 311 tip made its way to Banks’ office where 'the untaxed cigarette problem on Bay St.' was discussed, a source said.
"A day after the 311 call was made, cops arrested Garner for selling cigarettes without proper tax stamps.
"Cops found him in possession of 23 sealed packs of untaxed cigarettes and one open pack, officials said. He was arrested with untaxed cigarettes again on May 7, officials said.
"Then, a week before his death, Garner was 'warned and admonished' about selling untaxed cigarettes, a police source said."
So maybe the next question to ask is whether Garner had any untaxed cigarettes in his possession the day he died?
NYPD No. 3 s order over loose smokes led to Garner chokehold death - NY Daily News