The trial began Wednesday in Crown Point, Ind. Jurors first heard from Jada's mother, who said she left the baby with Castillo for two weeks and was suspicious of Castillo's boyfriend, Timothy Tkachik.
Last summer, police, relatives and residents searched for a missing 2-year-old girl for days. Jada was reported missing by Castillo. After the girl's body was found, Castillo and her boyfriend were charged with the murder. Tkachik entered into a plea bargain in which he agreed to testify against his girlfriend.
On Thursday, Tkachik described how he and Castillo used heroin, beat the child and when they discovered the 2-year-old was dead, they plotted ways to dispose of the body, which included two trips to the store to get supplies, including a container, cement and rope. He testified that he held the child's stiff, dead body as Castillo mixed cement in a round container. Tkachik said the couple did drugs throughout the ordeal and when the cement hardened around the girl, they dumped the container in a swamp, first trying to remove their fingerprints. Then he testified Castillo came up with the idea to report a false abduction from a gas station.
Under cross-examination, Tkachik testified that he agreed to a plea bargain to get a lesser sentence.
The state is planning on several more witnesses including FBI and local police officers who collected evidence and found Jada's body. The prosecution expects to rest at the beginning of next week.
The defense say they will call several witnesses. At this point, Castillo has not decided whether or not to testify in her own defense.
The Sun-Times Media Wire contributed to this report.