Answer:
They may have been able to avoid being arrested longer if they hadn't committed other crimes, such as stolen cars and setting fire to some heavy equipment.
Step-by-step explanation:
I think the main idea is that the police were very close to Manson and the family, they were even in jail, but the police hadn't realized they committed the crimes. It seems the family then became a little too confident, leading to the police arresting them for the crimes.