Protecting the White Bear by Terry Spear

An FBI agent, a polar bear shifter, attempts to rescue a kidnapped victim when a hot state trooper, also a bear shifter, gets in her way.

Trooper Andy MacMathan insists on being her backup. She wants to leave him behind. What begins as a kidnapping scheme twists and turns into something darker, while they turn into their polar bears to even the odds against their human foes.
Romantically falling for each other isn’t in the plan, but the heat between them sizzles. The mission to learn the truth deepens their commitment to each other while navigating the danger—if they can live long enough to solve the case.

If you love shifter novels, it’s time to check out the White Bear series.