Thomas Pierce

Thomas Pierce aka Mr. Smith is the hidden antagonist in the Alex Cross novel Cat and Mouse by James Patterson. Pierce is a vivisection serial killer with a guilty conscience and service in both Europe and the US.

Biography
Pierce, who was a partial follower of Gary Soneji, apparently had a moderately normal childhood in Laguna Beach, with no record of assault or crime. He had extensive medical education at Cambridge and Harvard University, and hooked up with Isabella Calais, turning into a deep and intimate relationship. They even planned to go on a expensive trip, until Pierce walked into Isabella having an affair with Martin Straw, a classmate, which resulted in him brutally murdering her.

His personality splitting from being riddled with guilt, Pierce took on the moniker Mr Smith., named after Valentine Smith. In psychotic breaks, Pierce would vivisect victims to death and have blackouts just after. The reason is their names were a puzzle to figure out his guilt: the first letters spelled “I murdered Isabella Calais”. The killings started in Western Europe, but the FBI realized Pierce was Smith and started luring him to the US to catch him in the act only having circumstantial evidence. Pierce worked in police consultation during the killings out of trauma from Calais' murder making him give up medicine. In his episodes, he sends himself messages daring himself to catch himself, to face his guilt and stop his crimes.

Pierce as Smith first appears to the latest victim in London, relaying how the live autopsy will feel and expressing "envy", despite pleas and panic from the victim. Cross refuses to take the case from FBI Agent Kyle Craig, but Cross visits Pierce. Pierce by then is working as an agent in London, and Calais' murder is painted as another killing in the spree. Pierce is obsessed with the notion Smith is trying to send a message in the murders. In the Smith personality again, Pierce leaves a phone call to the police to direct them to Inspector Drew Cabot's eviscerated corpse. Pierce then kills a young surgeon, Abel Sante, in Paris on his way home from his girlfriend, a surrogate for Pierce and another piece of his confession.

After Soneji's hired thug and childhood friend, Simon Conklin, attacks the Cross family and shoots Alex, Pierce accurately deduces at the scene Soneji wasn't responsible, as the kids were left alive and the attack was to make a statement. Pierce is the one to find Cross' badge, badly charred. When Cross goes into cardiac arrest at the hospital, Pierce visits with Craig and laments about Calais, still not remembering his guilt. He does, however, go with Sampson to meet Soneji's grandfather, Walter Murphy. The two find Soneji's first victims in the backyard - reduced to human and animal bones. Pierce then sends an email to himself As Smith and then has a blackout, receiving it with no memory and reading it's a confession of Sante's murder.

Pierce goes to Paris and, while struggling to profile the killings, sends himself an email to direct Interpol to Sante's body. They find him, his head disarticulated and cut in half, and "Smith" sends Pierce an email saying to "not trust" agent Sandy Greenburg. Pierce successfully deduces Conklin as Soneji's accomplice, but Conklin has too convincing an "alibi". Pierce theorizes Conklin directed Soneji's spree and burglarizes Conklin's house, coming up dry in evidence. Cross recovers and it's revealed he was never seriously injured; Pierce needed to believe that as, since the police know he's Mr. smith, they need Cross' case involving Pierce to better survey and catch him. Greenburg confirms Pierce was witnesses near the scenes of every recent murder. Agents are outside Conklin's house, but they're all too late: Pierce successfully butchered Conklin, even to the extent of extorting a confession of the attack on the Cross family before giving out and dying.

On a full blown spree, Pierce calls Cross, who's at Pierce's apartment and sees a collage of Calais all over, reporting a new victim, hollowed out of all organs. Afterwards, a prostitute is vivisected as well. Cross looks at the names of the victims and finally sees the hidden, literally spelled confession. Martin Straw, her mister, seems the likely final victim, but the police stop it and Pierce escapes. His last killing would've been his own, using the moniker as the last letter to complete his confession. But Cross tried to stop him, and in the scuffle Sampson shoots him dead.