Reward offered after third horse since November is killed in Southeast Texas

There's no more Sunshine for a 5-year-old girl in Southeast Texas.

That's because Sunshine, a horse belonging to little Arian Brock, was found dead earlier this week -- apparently killed by an arrow, Houston's Fox 26 reported.

But the story gets worse: Sunshine was a replacement horse -- donated to Arian by a rescue group -- for Sonny, the girl's previous horse, which was shot with a high-powered rifle just before Christmas.

“They didn’t kill him," Camie Brock, Arian's mother, told the station, referring to Sonny. "He was down and he was still alive suffering. And, I had to lay there and just pray with him until I could get someone to come euthanize him.”

This week the mother wrote on Facebook: "(M)y poor child doesn't understand why someone can be so sick in the head to do something like this!!!"

In November, a horse belonging to Riley Brett, another 5-year-old girl in the area, was also fatally shot, the station reported.

Local authorities are worried.

"If it turns out to be the same person, our concern is she or he going to be discontent with killing animals and then move on to humans," Capt. Ken DeFoor of the Liberty County Sheriff’s Office told Fox 26.

The cause of Sunshine's death was deduced from the aninal's injuries. But no arrows were found at the scene, the Dallas Morning News reported.

The other girl's mother also posted on Facebook after their family's horse was killed.

“RIP Chicken Nugget. You now have your wings and are flying high. You will never be forgotten. You will forever be…”

The family gave the girl another horse, named Chicken Wing.

Residents of Liberty County have put up a $20,000 reward for information leading to an arrest in the deaths of the three horses, Fox 26 reported.