What type of work does Mary's husband do in Lamb to the Slaughter?

In paragraph 16, Mary comments, "'I think it's a shame...that when a policeman gets to be as senior as you, they keep him walking about on his feet all day long."  So it seems that Patrick Maloney is of the police force but it never mentions that his position is anymore than that.  When the police arrive at the Maloney house to look into Patrick's death and possible murder, Mary recognizes many of the men, since her husband has been part of the force for a long time.  But the story does not mention that he is a detective or sergeant or captain or anyone with a more particular title.  It does also appear that Mary and Patrick have been married for some time if she knows his co-workers, yet she appears to be pregnant with their first child, as no other children are mentioned in the story.