A second arrest has been made in the death of a Stamford mother of four, police say.

Police say the victim's mother-in-law, 60-year-old Mercedes Collazo Martinez, has been charged with cruelty to persons.

Iris Lopez, 36, died Tuesday after she was rushed to Stamford Hospital with a massive brain bleed and dozens of bruises on her body just the day before.

Police initially arrested her husband, Hector Lopez, who is accused of denying his wife medical care by refusing to call 911.

Lopez's mother eventually got an ambulance to their Southwood Square apartment Monday evening but police say that happened more than 12 hours after Martinez noticed the victim needed help.

"Iris Lopez was not given medical care and clearly her condition warranted it," says Lt. Tom Scanlon of the Stamford Police Dept. "She was in distress, unresponsive from early in the morning and that continued throughout the day Monday."

Martinez's attorney, Lindy Urso, tells News 12 that his client willingly sat down with police twice before contacting him. He says that Lopez was under the care of her husband and Martinez was at work much most of the day.

"This is clearly just a squeeze play by the police," Urso says.

Investigators, however, believe Martinez has withheld information.

Martinez's attorney says he will fight to get her bond lowered when she is expected to be arraigned Monday morning.

Anyone with information about the case is asked to contact police.