Previously House Trained Pooping and Peeing in House?

I have a 1.5 year old Schnauzer who was perfectly house trained; I trained him myself. When we adopted another 9 month old female Schnauzer who I still cannot train, he also began to pee everywhere. I have tried positive reinforcement with treats.

They go out in the morning, afternoon, and at night after eating. I place newspaper and the female poops and pees there every night and she goes outside as well. When we leave even if it is for an hour she will pee 2 or 3 times inside. I cannot get her to only go outside and so my male Schnauzer who was already trained is getting the bad habit. I do not know how else to train them.

By Farrah