Emma Roberts: Caleb Johnson Killed It on 'American Idol'!

Emma Roberts runs some errands as she steps out on Wednesday (March 19) in West Hollywood, Calif.

The 23-year-old American Horror Story star tuned into American Idol last night, and was very impressed with one of the contestants!

“#AmericanIdol @CalebPJohnson killed it!” Emma tweeted.

PHOTOS: Check out the latest pics of Emma Roberts

“Thanks for watching last night if you enjoyed the performance you can find the studio version in the link below !:)” Caleb wrote on his Twitter account – download his song on iTunes.

FYI: Emma is wearing an Aqua top and Penelope and Coco shoes.

10+ pictures inside of Emma Roberts running some errands…