Two guys were talking (police officer investigating a certain case and a general trying to help him).

At the end of their conversation the general said: Regular reports, usual channels. But check back in with me tonight. If you need support, don't hesitate. We'll do what we can.

I understand it means: Report to me regularly, use the same channels (probably by phone) and ... check back in with me tonight.

It sounds like he wants him to report to him twice?

First I suppose by phone (regular reports, usual channels) and then personally (maybe he wants him to come and meet him again?) "chech back with me tonight", which I think means "report back to me".

Do you think my understanding might be correct?

It just means 'give me reports regularly, in the usual way. But also, contact me tonight (maybe by phone, maybe in person)'.

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Thank you, Clive!
"Use the same channels" would just mean whatever the normal reporting procedure is, which might be filing paper reports at the end of a shift, or after an interview or investigation procedure on a case, as in case notes, or filing those things electronically, etc. It would probably not mean by phone, as routine reporting is seldom done by phone, but is usually either a paper record or, more likely these days, an electronic record of what goes on during a shift or an investigation.

"Check back in with me tonight" could, as pointed out, mean call me on my cell (mobile) phone, e-mail me, call my work line, call me at home, etc., but the gist of it is that he is asking that there be some contact between them that evening so that he can be updated on what is going on.