GLENDALE, Ariz. -- One man is in custody and another has life-threatening injuries after an argument over a dog turned into a stabbing, police said.

A woman and her ex-boyfriend were arguing in a mobile home park near 71st Avenue and Northern Avenue, when another man, identified as William Langley, became involved in the altercation, police said.

Glendale police said Langley stabbed the victim, who is in his 50s, multiple times.

Paramedics airlifted the victim to the hospital with life-threatening wounds.

Neighbors in the park said they heard the arguing, then silence and then saw all the police cars.

"It sounded like a woman and man arguing," said Donna Rockwell.