"They said they have identified someone, and they have warrants for the arrest, I don't know who they've identified, they obviously want to keep that to themselves until they actually make an arrest, I can understand that. We'll find out when we get there," said Castillo.
Castillo, a member of Michael Jackson's defense team during the pop singer's child molestation trial, is hoping his expertise will help police in Ambato, Ecuador.
That's where 26-year-old Lopez was brutally murdered last month.
The Cal State student traveled there to volunteer and visit relatives but was found one night in a park with her throat slit and stabbed several times on her chest and back.
Authorities say the suspect was well acquainted with Lopez.
Lema believes it is a man that had been stalking her daughter.
"I don't know if it was jealousy, I don't have an idea," Lema said, "I cannot answer that because she's never had enemies there."
For week, Lema had been trying to get police to investigate the case.
Now, after much media publicity, she is getting help from high ranking officials in both the U.S. and Ecuador.
Earlier Sunday, hundreds of people showed up for a memorial for her daughter.
Sunday night, Lema returns to Ecuador with new hope that justice will be served.
"People who was praying for me, people who were together with me and gave me all their love, I really appreciate that. They make me feel like I'm not alone," said Lema.
As soon as she lands in Ecuador, Lema and Castillo will meet with the officials in charge of the murder investigation. Authorities have warned Lema not to visit the home where her daughter had stayed, because it might be too dangerous.