Crackling scenes mix with clunkers, clever twists meet cliches and its all a hash when it comes to justifying the “team” set up in this mass shooting spree thriller “To Catch a Killer.”

Whatever its other failings and successes, this film has a script that never manages to justify its central premise, pairing up a somewhat inept and troubled young Baltimore street cop with a senior FBI agent brought to solve a New Year’s Eve mass shooting so cunningly planned that we know it won’t be the shooter’s last act of wanton slaughter.

Shailene Woodley plays Eleanor Falco, a 30ish cop whose New Year’s Eve unruly diner call is interrupted by random murders all over central Baltimore. One of the film’s more chilling sequences is the single shot sniper shootings in a hot tub party, a glass elevator, through windows and picking off people at an outdoor skating rink.

Chaos reigns, and Falco finds herself at one shooting scene as forensics quickly determines where the shots came from via laser-angle tracking. When SWAT and other uniforms pile into the high rise condo that gave the shooter his or her vantage point, it blows up.

Falco is the one with the presence of mind to get her fellow cops to videotape other residents as they’re evacuated. That, and the way she faints in the smokey ruins of that apartment, and yet still eyeballs a possible clue, is all it takes for bossy, territorial Special Agent Lammark (Ben Mendelsohn) to take her in, call her a “BPD liaison” and make her his special project, his extra “eyes” on a tragedy that has drawn the world’s attention even as the mayor and governor and their aides figure out ways to CYA.

“Who IS this?” and “Why is she even HERE?” is only asked once in this Damián Szifron (he also directed) and Jonathan Wakeman screenplay, even as it hangs over every damned scene to follow.

Something in Falco, her attention to detail despite wearing “burnout” all over her face, has Lammark asking “What IS it, Eleanor?” over and over, in meetings, on crime scenes and in a helicopter running them all over the city.

We never get a good answer, despite her occasional clever insight.

Of course the screenplay gives each of them secrets, the insecure “credit” seeking FBI agent and the overwhelmed, squeamish policewoman who is patronized, stereotyped and sometimes listened to as this investigation never quite seems as urgent as any shooting with that high a body count should be.

The Woodley/Mendelsohn teaming works well enough, in terms of chemistry. The supporting cast is a fairly colorless lot, with virtually none of them given a scene or enough good moments/lines to make an impression.

And I have never seen a thriller pair-up people who shouldn’t be paired-up and yet are paired-up anyway managed less gracefully. Even a “job shadowing from the Academy” excuse would have been better than this, or at least given us something to hang onto.

The script does a half-hearted job of paying lip service to the buzzwords and politics surrounding mass shootings, “terrorist” or “maniac,” “gun hoarder,” with ex-military or foreign born idealogue or aggrieved angry white male considered, and dismissed, because they’re looking for a “person,” not an archetype.

“He didn’t come here to die and does not want to be found,” Lammark pep-talks his underlings. “We’re going to disappoint him.”

But as Mendelsohn’s agent grandstands and talks of the “book” he’ll Haberman/Bolton out of this crisis, defends his turf, flips between paranoid and self-pitying, coddles Falco and publicly berates her, the odd engrossing or well-conceived moment pops up and makes us take notice.

Then even that fades into the background as we, one more time, wonder “Why is she even HERE?”

Rating:  R for strong violent content, and(profanity) throughout.

Cast: Shailene Woodley, Ben Mendelsohn, Jovan Adepo, Michael Cram and Ralph Ineson.

Credits: Directed by Damián Szifron, scripted by Damián Szifron and Jonathan Wakeman. A Vertical release.

Running time: 1:58