Bybee, Catherine. Richter series #2

"On a fateful night in Las Vegas, FBI agent Leo Grant is working on a critical detail in a high-profile child prostitution trial when a beautiful woman jumps into the path of a bullet meant for him. Little does Leo know that the woman is Olivia, an ex-assassin who is seeking redemption one good deed at a time. One minute, Olivia is lunging in front of Leo on the Vegas Strip. The next, she's waking up in the hospital in a haze of pain with no memory of her past, her enemies, or even her own name. With Olivia suffering from memory loss and completely unaware of the danger she is in, it's up to Leo and Neil MacBai's team of operatives to keep her safe. With Olivia and Leo both unaware of her past crimes, the two have little reason to avoid their growing attraction. Slowly her past seeps in through the cracks as she struggles to find the answers of who she is. When the veil is lifted and her dark past is staring her down, Olivia must turn her back on Leo and the love she can never allow herself to have, and race to find her would-be killer"--