BAKERSFIELD — The former firefighter from Hesperia who pleaded guilty last month to voluntary manslaughter and other charges related to the killing of BNSF Railway worker Robert Limon is expected to testify in court here Tuesday.

Jonathan Hearn was initially scheduled to testify last week and again on Monday, but those dates were bumped. If Hearn testifies Tuesday against Sabrina Limon — his former lover — he will do so on his 27th birthday, according to his date of birth provided in jail records.

At her Jan. 10 arraignment, Sabrina Limon, 37, pleaded not guilty to murder conspiracy, solicitation to commit murder, attempted murder, poisoning and accessory charges, according to a previous Daily Press report.

Her not guilty pleas came one day after Hearn entered into a plea deal that resulted in a looming prison sentence of up to more than 25 years, as well as his testimony against Sabrina Limon.

The whirlwind of recent updates related to the 2014 shooting death of Robert Limon, 38, of Helendale, started when Sabrina Limon was arrested in Camarillo on Jan. 7, days before Hearn’s jury trial was expected to begin in Kern County.

According to the Bakersfield Californian newspaper, the poisoning charge relates to a previous attempt on Robert Limon’s life involving arsenic and banana pudding, the slain man’s favorite dessert.

In court documents, Hearn admitted to the poisoning plot on Jan. 3, and detectives found arsenic trioxide, which Hearn purchased for $136.41 using a prepaid credit card and a fictitious name, in a garage during their investigation into the killing, the Californian reported.

Hearn and Sabrina Limon initially discussed killing Robert Limon in a car accident, a fire or by poisoning, deciding the last was the best option to avoid getting caught.

The plot progressed to the extent that Robert Limon took the poisoned pudding to work, according to the Californian, but Sabrina Limon called her husband and instructed him to throw it out after she and Hearn feared the arsenic would be found in his blood during a criminal investigation.

Robert Limon was shot to death following a work shift at a BNSF industrial complex in Tehachapi in August 2014. Both Hearn and Sabrina Limon were arrested in November 2014, but Sabrina Limon was later released due to insufficient evidence against her.

Hearn’s attorney, Clayton Campbell, previously said he expects Hearn's testimony will provide crucial evidence to the prosecution's case against Sabrina Limon.

Matthew Cabe can be reached at MCabe@VVDailyPress.com or at 760-951-6254. Follow him on Twitter @DP_MatthewCabe.