The Voice or one’s female-lead detective or PI in crime fiction--above all elements-- must be consistent, just as your choice of words, control of weak qualifiers, control on adverbs and adjectives, down to your grammatical skill all impact on VOICE, the final product, your lead character’s VOICE controls the novel and reassures the reader even as it lulls him or her into "becoming" the leading lady.

The sound of the bell your narration and dialogue ring in the reader’s head must be unique, believable, likeable, even loveable, and if you cannot make it ‘sing’ then at least make it ‘clear’. The difference between confusing readers, and\or sounding wishy-washy, or sounding like unto one who is awash in political mish-mash (like someone who cannot commit) as opposed to an assured, authentic, absolute voice (like someone who is committed) is in one’s authorial voice, and this compelling voice relies on absolutes over qualifiers in the narrative. 

This is even more true of the feminine lead written by a male author! To pull off the so-called "impossible" –getting into the head of the opposite sex and understanding from this point of view, surprisingly enough, surrounds elemental, fundamental reliance on a "woman of substance" in the VOICE. If you are a female author struggling with how to get into the psyche and ‘mindset’ of a male lead, just reverse what I say here.

VOICE in dramatic, commercial fiction in particular relies heavily on strong Active Voice over weak passive voice. These basic grammatical decisions (word choice, exorcising qualifiers for absolutes, using active verbs over passives and cripplingly slow helping verbs, and exorcising the verb to be) are the crucibles about which E.B. White wrote in The Elements of Style and supported by the fine book Writing Shapely Fiction by Jerome Stern. 

Style comes out of extremely small elements you choose to make work for you--or items you fail to utilize. As small as the choice difference between say the word before and ago, maybe and perhaps, this is "shaping" voice. This "becomes you"--BECOMEs your style. If you choose a folksy or shoddy or simplistic or complex or formal or informal voice, your reader will know it from the outset and is normally willing to follow it so long as this voice remains consistent and consistently believable. So is VOICE the single most important element of your story? Absolutely, and yet it is created of all the other elements and choices you choose to make from setting to dialect to no dialect to the difference between between and betwixt, leaped and leapt.

All good writing relies on the reader ‘falling for’ your narrative voice, the point of view speaker, the mind you set your reader down into comfortably or awkwardly. If it is an ill fit, little wonder as an author is a trick cyclist on the unicycle juggling twenty four plates in the air, spinning each ‘choice and decision and element’ at the end of long sticks. Each plate, each stick, each prop is an important element, but they all culminate in the overall effect your story has on the reader’s ear and mind’s eye. 

If I had said the writer is LIKE a trick cyclist rather than stating it as a fact, it rings a different bell, sends a different and less powerful impact. The use of LIKE and AS is terribly overdone in some "voices" in female-lead crime fiction. The use of passives, especially the WAS verb—a major killer of action and visualization—also riddles most fiction and especially in the first person narrative along with the personal pronoun references to the narrator: I, me, my, mine, myself, often using the personal pronoun three and four times in a given sentence. 

What a reader hears and pictures comes about as result of our giving him a believable SOUND in his head—the author’s voice, or the narrative voice (not always the same) or the character’s voice, along with providing Kodak moments in the reader’s head that look, feel, taste, smell, and sound like images. The human brain sorts its mail via images, so it behooves us to use verbs that carry the weight of an image. We call this simile and metaphor and extended metaphor, but the absolute is even more powerful than these.