A man has been arrested after poo on his shirt matched the excrement being held by a dog owner he allegedly robbed at knifepoint.

William Carroll, 62, from the town of West Little River in Miami-Dade County in the US state of Florida, has been arrested and charged with armed robbery and battery following the attack on 28th March.

The woman, name not disclosed, was returning home from walking her pet pooch when Carroll attacked her.

According to local reports, the victim stopped at a stairway at her home on Northeast 7th Avenue while her dog relieved itself.

As she scooped up her pet’s mess, Carroll attacked her from behind and shoved her against a wall.

He then reportedly brandished a knife and started to strangle the woman.

During the attack, Carroll attempted to snatch the victim’s bracelets and watch, but ended up running off with her bookbag and another bag containing her purse and credit cards, according to reports.

A male witness saw the attack and yelled at Carroll that he was going to call the cops with the suspect replying “shut up”.

He then fled the scene, but was stopped by police officers nearby a short time later.

The police said Carroll was out of breath from running and that some of the snatched credit cards were found nearby.

Cops also found the knife he allegedly used as well as the woman’s bookbag.

While being quizzed by officers, the suspect denied any involvement in the robbery, however cops noticed a brown stain on his shirt that match the dog excrement at the scene, according to reports.

The victim also identified the man as the suspect in the attack. She reportedly sustained minor injuries on her neck after allegedly being strangled by him at knifepoint.

Carroll is being held without bond for armed robbery and battery as the police probe continues.