single = not married? If it means "one person to himself", it would be "alone".

[NewHopeR]

Am I on the right track?

Context:

One official said that the misconduct in Cartagena, Colombia, ranges from personnel, including at least one veteran supervisor, who knowingly took prostitutes to their hotel rooms to at least two employees who had encounters with women who investigators now believe were not prostitutes. One officer, who is single, met a woman who investigators concluded was not a prostitute in a chance encounter at a bar before taking her to his room, according to the official.

More:
Misconduct in Colombia Varied, an Inquiry Finds

[Raymott]

Am I on the right track?

Context:

One official said that the misconduct in Cartagena, Colombia, ranges from personnel, including at least one veteran supervisor, who knowingly took prostitutes to their hotel rooms to at least two employees who had encounters with women who investigators now believe were not prostitutes. One officer, who is single, met a woman who investigators concluded was not a prostitute in a chance encounter at a bar before taking her to his room, according to the official.

More:
Misconduct in Colombia Varied, an Inquiry Finds

Yes, 'single' here means 'not married'.
They are trying to make the point that there was a range of 'badness' about the misconduct (Their conduct was 'varied'). At one end, you have married men hiring prostitutes, and at the other you have single men meeting new 'friends' in a bar.

[NewHopeR]

Thank you