Mischa Barton and Delaney Williams Guest on 'Law and Order: SVU' (VIDEO)

Mischa Barton showed up on 'Law and Order: SVU' (Wed., 9PM ET on NBC) as a prostitute trying to put away a hooker killer. And good for Barton. She's had her ups and downs, but hopefully she's getting her career back on track.

Equally as interesting is seeing Sgt. Landsman (Delaney Williams) from 'The Wire' playing defense attorney John Buchanan. Hope to see more of him on the screen, too.

Watch the video after the jump.Mischa Barton showed up on 'Law and Order: SVU' (Wed., 9PM ET on NBC) as a prostitute trying to put away a hooker killer. And good for Barton. She's had her ups and downs, but hopefully she's getting her career back on track. Equally as interesting is seeing Sgt. Landsman (Delaney Williams) from 'The Wire' playing defense attorney John Buchanan. Hope to see more of him on the screen, too.