Fans of CBS' "Criminal Minds" have a lot to look forward to when the long-running drama series returns with all-new episodes next month, including the return of "CSI" star Marc Vann.

In the next episode, which is entitled "Lockdown," the BAU will go on a hunt for a killer at a maximum security prison after two prison guards are murdered. As a result, viewers will get an inside look at the prison system, notes Carter Matt.

CBS also released the official synopsis for "Lockdown," which reads as follows, according to Carter Matt:

"When two guards at a privatized maximum security prison in Texas are murdered, the BAU suspects that more than one UnSub within the prison could be at work, on CRIMINAL MINDS, Wednesday, March 4 (9-10 p.m., ET/PT) on the CBS Television Network. Series star Thomas Gibson directed the episode. William Ragsdale ('Justified,' 'Herman's Head') guest stars as prison captain Dale Shavers."

According to TVLine, Vann, who played Sheriff Conrad Ecklie on "CSI" will guest star on Episode 18 of Season 10, titled "Rock Creek Park." He will play an FBI agent in the Organized Crime Division who will offer aid during a special investigation.

The first time Vann appeared on "Criminal Minds" was in Season 3's episode titled "Penelope."

In addition, TVLine reports that "Rock Creek Park" will precede the show's planned spinoff series, which will revolve around a "globetrotting BAU team that tends to Americans in crisis abroad."

"CSI: NY" actor Gary Sinise has also been cast on the spinoff as Jack Garrett, a 20-year veteran of the FBI and leader of an elite BAU team that investigates cases involving Americans abroad.

"Criminal Minds" showrunner Erica Messer is behind the potential spinoff.

Season 10, Episode 15 of "Criminal Minds," "Lockdown" will air on Wednesday, March 4 at 9 p.m. EST on CBS.