It had to start with the doctors, so it didn't start moving till the research led there. Police are very risk-averse. Even if they see drug policy ruining live

It had to start with the doctors, so it didn't start moving till the research led there. Police are very risk-averse. Even if they see drug policy ruining lives, they will assume those drugs are very dangerous and have no benefits unless they have it on very good authority otherwise and doctors are the only people with the authority on that subject to really convince police. Also, police are one of the few groups with the authority to convince politicians, who are generally very suspicious of doctors who want to try and legalise drugs.