Story highlights Rosemary Vogel, 65, is charged with attempted first-degree murder

A nurse, she allegedly put feces-laced fluid into her 66-year-old husband's IV

The couple was in his recovery room following his surgery

"This is the first that I've heard where fecal matter has been injected into an IV," officer says

An Arizona woman is accused of injecting feces-laced fluid into her 66-year-old husband's IV as the couple was alone in his recovery room following his surgery, police said.

Rosemary Vogel, 65, of Sun Lakes, was arrested after a warning alarm on the IV monitor sounded Thursday. She is now charged with attempted first-degree murder and vulnerable adult abuse, according to police and CNN affiliate KTVK

Her husband, whose name wasn't released by authorities, is expected to survive as he recovers in Chandler Regional Medical Center, said Sgt. Joe Favazzo.

KTVK reported that Vogel is a registered nurse and was a hospital employee at one time, according to the probable cause statement written by police.

Vogel's attorney couldn't immediately be reached for comment.

"This is the first that I've heard where fecal matter has been injected into an IV system," Favazzo told KTVK.

After the IV monitor alarm sounded, the hospital staff entered the recovery room and found Vogel manipulating her husband's IV, police said.

The hospital found a brown substance in the IV line and immediately removed it from his arm, police said.

Vogel allegedly tried to drain the fluid from the line into a waste basket, but a nurse intervened, police said.

A test revealed the fluid contained fecal matter, police said.

Vogel's purse contained three more syringes. Two of them contained fluid, and the third appeared to have trace amounts of fecal matter, police said.

Police don't have a motive, Favazzo said.