LOS ANGELES (CBSLA.com) — Los Angeles police are searching for a suspect who allegedly left a dog for dead in an alley last month in North Hollywood.

On July 4, a witness saw a man pull a critically injured 2-year-old pit bull from the bed of his truck and dump it in an alley between Kittridge Street and Hamlin Street, one block east of Laurel Canyon Road, according to authorities.

The suspect was then confronted by the witness before he fled the area.

The witness and a Good Samaritan helped rescue the dog named Indy, which police said may have been tied up and dragged from behind the truck, and called the Shelter Transport Animal Rescue Team (S.T.A.R.T).

“When we got the call and saw the videos, we thought, ‘We have to put this dog down…it’s suffering,’” said Steve Spiro of S.T.A.R.T.

Authorities said the dog’s injuries were extensive. His paws and claws were worn out; the pads of his feet were gone. He had lacerations from the waist down and burn-like injuries all over his legs.

“This type of cruelty is so gratuitous,” said Rene Ruston of S.T.A.R.T. “These are cruel people. They will stop probably at nothing.”

S.T.A.R.T, which has been caring for the dog for the past month, has been overwhelmed with donations from around the world. A $15,000 reward has been offered for the arrest and conviction of the truck’s driver.

“This doesn’t just stop at animals. It goes on to children, it goes on to people, it goes on to a whole host of other crimes,” said Spiro.

“What we do know is that it was intentional,” said Ruston.

While Indy is up for adoption, he still has to undergo more medical treatment.

The suspect’s truck was described as a possible late 1980s white Toyota pickup, with dark stripes on the side of the vehicle, a toolbox in the bed of the truck, large off-road tires, a sunroof, and small extra cab windows.

Anyone with information about the crime was urged to contact LAPD Animal Cruelty Task Force, Detective Support and Vice Division at (213) 486-0450 or go to www.startrescue.org.