I don’t mean to be cruel. But I don’t understand a suicide watch of a murderer. If he kills family and then wants to kill himself, why stop him? I guess keeping him alive to hear the verdict of guilty is good.
Having worked in jails and prisons, I can say that the average employee (whether uniformed or not) is humane and dislikes being traumatized any further than necessary. There are medical personnel working in jails and prisons, too - and those doctors, nurses and others are there for a reason - we don't just throw people in cells and let them waste away or develop bed sores, etc. So if suicidality is noticed, it is addressed.
Where I currently live, all new deputy sheriffs are trained for community policing. Their first assignments are the jails.
Being a jailer is rather awful, especially at the intake/court adjacent jail. They work that for two years. They must never lose their tempers or treat inmates in any way outside of regulations. The prisoners assault the jailers, heckle them, spit on them, etc. But the goal of the training and the job is that the jailers must preserve these people until their trials (once sentenced, we have another couple of jails and of course, prisons in the state). Some young deputies have lost their jobs for responding inappropriately - because the job is to protect and to serve.
While in jail for trial, the person is still innocent, which is a further reason. Police take it really seriously if they can't deliver a living person to the courts and to prison, if that's what's coming next.
Having said all that, I have myself muttered something like your sentiment to a psychiatrist (family member). Despite having truly negative feelings about some patients, a doctor must still do their best to prevent harm to the person, including suicide (even if they're hellbent on it and blockaded with explosives in an apartment building...)
This training plan in my county results in far fewer officer-involved incidents of misconduct compared to two nearby counties that do not require two years of patience training in jail. In my county, after 2 years in the jail, they spent 1-2 years as a bailiff before they go on regular patrol (and some of them go back to being bailiffs, as a preference, as patrol isn't for everyone, either). And our longterm jail has won awards of various kinds (mostly to do with recidivism but also with inmate and employee health - we don't have as many jailers out on work-related disability as the next door counties).
IME/O.