Police have arrested the third person accused of stealing Joaquin Rivera's watch as he sat dying in the waiting room of a Northeast Philadelphia hospital on Nov. 29.

Jannira Walker, 21, was arrested Saturday on charges of robbery, theft and related offenses. Walker's last known address was the 1300 block of W. Erie Avenue, but police said it was possible that she, like the others arrested in the theft, is homeless.

Rivera, 63, was a popular high school counseling assistant, musician and community activist. He died Nov. 29 after going to the Aria Health-Frankford Campus with pain in his chest and left arm. According to some witnesses, he sat unnoticed for nearly an hour before hospital staff realized that he had died. His death has sparked outrage in the city's Latino community, with a group of protestors calling for broad healthcare reform.

In addition to Walker, police have arrested Martin Smith and Richard Alten. Both face the same charges filed against Walker. Rivera's watch has been recovered, according to police.

The death is under investigation by the state Department of Health and the hospital and the theft is being investigated by police.

Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com