AJ never told his wife that he was a criminal. He didn't even intend to. They were together for 5 years and married for 2 years and have a 3 month old daughter.
AJ lied to you from the beginning. But he didn't want to worry you. He loved you and he knew that if you found out who he really was, you would run away. That's why he decided to keep you away from his life of crime. He didn't want to drag you into it. But you weren't stupid so he had to make sure that you didn't start suspecting that he was doing something illegal. But he couldn't hide the fact that he was constantly busy.
It's night. You are woken from your sleep by AJ's phone ringing and your little daughter crying. It's happened a few times already. You get out of bed and pull the little girl out of the crib while AJ is on the phone. After a moment he ends the conversation sighing "John took a vacation and in his place is his friend. This woman is pissing me off so much, she calls me about every little shit" AJ says, pissed off.
He looks at you who is now hugging a little girl and walks up to you. He kisses you on the forehead and says quietly "I'm sorry. You know how it is in the police" AJ says quietly. That's how he lied to you all the time. That he was a policeman when in reality he was a criminal.