Zero Days

 Zero Days by Ruth Ware  307 pp.

Jack (Jacintha) and her partner (and husband) Gabe own a business where they try to penetrate building security both physically and online so that they can give the companies tips on how to improve.  Jack is at a building doing the physical aspect of the security check (and hooking Gabe into the online aspect) when she is caught by security personnel.  They don't believe her when she said she was hired to do the check since the company contact is not answering his phone, so the police take her into custody.  Her former boyfriend (Jeff) is a police officer and when he finds out what is happening gets her freed.  When she gets home to her house, she finds Gabe with a slit throat.  Because she is in shock, she doesn't call the police immediately which leads them to question the timeline of her actions and before she know it, she is a suspect.  From there, Jack goes on the run and is nearly caught several times.

Despite figuring out who the bad guy was fairly early on, I did not know the motive immediately.  The book had an action movie feel to it once Jack was on the run and I felt the author played fair with the mystery aspects of the story.