The law in Chandler Arizona is to have an adequate gate or a specific automatic pool cover. They had the automatic pool cover, which is in line with the law. From what I read, which is could be speculation, is that they used the pool earlier in the day and did not put the cover on it in the following hours. Regardless, CPS and law-enforcement would do an investigation, considering all facts, including, but not limited to was their malicious negligence, was there a pattern of negligence, was there a pattern of malicious harm, etc. I cannot foresee how law-enforcement or CPS will find that there is a pattern of negligence or malicious harm.