Can deceitful family sabotage your chances as a police officer?

I have a clean background, I have a lot of family that is ex military, Cops, or guard backgrounds. I was going to apply to work at the police department. My mother in particular is very against me being in any kind of Guard, Cop or military profession since they say its dangerous and I might die. I really dont care about how cowardly my mother is in that aspect.

I know that they have to speak to families and if your family says something bad about you it can hurt your chances. I know my dad or his side of the family would not stop me. Especially since my father worked for the sheriff department but I dont trust my mother. Is there chances she could blow it for me? Since she wants to ruin my life and constantly control me?

She actually would rather have me doing something safe like work like a janitor for the rest of my life. Since I was little I would always be the person to "Throw the book at someone" and I always make sure to learn all the rules and follow them. People usually note that about me.

I was also very obsessed with criminal psychology and trying to figure out how their brains worked. Which everyone seemed to hate for whatever reason. Why would you not want to understand how criminals and crazy people worked? That means you could A.Begin to fix/help them B.Be prepared if they ever go off on you. You can not defeat your enemy if you do not understand them. If they understand you better they will always win.

I was always the nerdy perfect goody goody and I enjoy enforcing rules and have a very orderly/Strict type of personality. I know its dangerous but being a cop is not the same as say shooting up Arabs in Iraq and risk of having your food blown off.