The established police culture discourages honest, integrity driven people from joining their ranks. For every explosive story about retaliation towards an honest cop, there are likely dozens more who were ostracized or denied promotion for speaking out against the bad cops around them. Then we wonder how we can have situations with 4 or more cops where all the cops were willing to go along with a lie. This cancer is ingrained in their culture, within even the simple courtesy of not ticketing fellow cops.
https://danwang.co/statistics-on-police-fatalities/
Based on fatalities/officer, police work has gotten steadily safer since the 70s. Too many cop apologists don't bother to look at stats.