Russel Acker was a former consultant with the IMF and the main antagonist in the episode “Reprisal”.
In 1975, Acker was in a car accident and suffered a severe concussion. When he recovered, he was a different man. He was now mentally unbalanced and prone to fits of rage and violence. Acker was quickly dismissed by the IMF. Subsequently Acker founded his own research lab and with several patents under his belt, he became quite wealthy.
But he also began murdering attractive young women. The authorities were unable to prove his guilt and Acker began openly taunting the police, believing himself to be untouchable. By the time the IMF Secretary became involved, eight women were dead. Ultimately, Jim Phelps was called in to take him down. He and a team of three female IMF agents (Laura Ann Wilson, Lisa Casey and a third agent known only as Marilyn) were able to see to his arrest. In 1977, Russel Acker was declared criminally insane and incarcerated in a San Francisco mental hospital.
Russel spent the next 12 years in his cell seething with anger and spent every waking hour plotting his revenge on Phelps and his team. Acker was still able to access funds from his secret account and bribed a hospital orderly named Talbot into becoming his accomplice. Talbot and Acker were able to fool the security cameras using a recorded loop of Acker alone in his cell. Acker could now leave the hospital undetected for short periods of time. Time that he used to acquire the materials he needed to make latex masks to change his appearance.
In 1989, Acker escaped from the hospital again, disguised as Talbot. Once free, he disguised himself as Phelps to carry out the murder of Laura Ann Wilson.
Phelps was identified by the police as the prime suspect. The IMF knew Phelps could not have committed the crime as he was on a mission in Thailand at the time. But since civilian law enforcement agencies are not privileged to mission records, the IMF could not clear Phelps. The most the IMF could do was delay the police from issuing an arrest warrant. The IMF then gave Phelps the mission of clearing his own name.
Phelps and his team desperately scrambled to locate the other female IMF agents Lisa Casey and Marilyn who were now in danger.
Acker, again disguised as Phelps, was able to kill his next victim, Marilyn. Dozens of witnesses saw "Phelps" commit the crime and now the police were closing in on the real Phelps.
Acker booby trapped the computer keyboard in Phelps' apartment with the same sedative chemical he helped develop for the IMF. With Phelps seemingly unconscious, Acker left the apartment posing as Phelps and was now on his way to kill his final victim, Lisa Casey. But Phelps and his team were prepared for this - Phelps had taken the antidote to the sedative beforehand.
Acker (disguised as Phelps) attempted to strangle Lisa Casey in her dance studio. Lisa escaped his grasp while Phelps and the other IMF agents recorded Acker removing his latex mask and incriminating himself as the true killer.
After Acker was again taken into custody, Lisa asked “Will he ever come back?” to which Phelps responded “Not from where he's going.”
- Grant Collier mentioned that his father, Barney Collier worked with Acker at the IMF laboratories and developed many of the tools and technology still used by the IMF field agents including the latex mixture used in their masks.
- No actual dates were given in the episode. Only references to "12 years ago" or "10 years ago". I am taking the actual air date of the episode "Reprisal" which was 04/15/1989 as the approximate date around which the events took place.