Clinical depression isn’t just a lack of religious teachings. You can be a good Christian and pray with all your heart for God to take that cup away from you and still be depressed. Sometimes God’s answer to your prayers is no.
Could these officers been helped by reaching out to the chaplain? Maybe.
By no means are all suicides a big complicated deal, a lot of suicide is simply seeing it as a valid option and doing it.
A lot of suicides could be stopped by simply pointing out that the person doesn’t want to go out by shooting the bird at God, explaining that absolute to men in articles and pamphlets when the subject is mentioned would make a lot of them have to take the suicide option off the table and put them back to searching for other ways to deal with whatever they are dealing with.