Johnson is accused of fatally shooting her husband in a car on Feb. 21, 2009, near a 91 Freeway off-ramp. She then allegedly drove the car to her parents' home in Compton, where Sheriff's deputies found Lemons in the front passenger seat.
Johnson told sheriff's investigators and friends that it was domestic violence, that her husband had become abusive.
Tuesday the L.A. County District Attorney charged Johnson with murder.
The D.A.'s office isn't saying what turned the case, but nearly two years after that shooting investigation, Johnson is behind bars charged with murdering her husband.
"I was very happy about this. It took a long time to get it, but we got through it. So I'm very happy about this," said D'Marco Lemons, Marcus Lemons' son.
Friends of the victim say that he was never a violent man.
Johnson worked out of the West L.A. office. Since the shooting, she had been in a non-enforcement administrative position. Tuesday though, she was placed on administration leave without pay. She remained behind bars on $2 million bail.
The California Highway Patrol released a statement Tuesday:
"Tomiekia Johnson has been an employee with the CHP since September 2002 and was assigned to the West Los Angeles area office. Upon notification of a criminal investigation into this off-duty incident, Johnson was immediately placed in a non enforcement administrative position on February 22, 2009. Following the conclusion of the Los Angeles County Sheriff's Department criminal investigation and in conjunction with today's arrest, the CHP acted quickly to put Johnson on administrative leave with no pay. CHP is cooperating with the Los Angeles County Sheriff's Department and appreciates the efforts of all of those who have worked hard to investigate the case and bring the facts to light. All CHP employees are held to the highest standard of conduct. These are serious allegations and are being treated accordingly by CHP management. The department will not tolerate actions by any of its employees that violate the public trust and bring discredit to the organization, its time honored traditions, and institutional values. This employee's alleged action should in no way reflect upon the thousands of hard working, dedicated, and professional men and women who make up this department." -- Sgt. Denise Joslin, CHP Southern Division