"All we have are reports. The last time we know, for a fact, he was in school and that was April 30th," HPD Executive Assistant Larry Satterwhite told reporters Monday night.
On Tuesday, through the tears, Sam's grandmother, Tonya Olson, begged for help in solving his disappearance. She spoke with ABC13 less than 12 hours after police finished executing a search warrant in southeast Houston.
"Everybody loves you and misses you. We're going to see you soon. I promise Sam. I'll never give up," she said.
WATCH: Grandmother of missing boy: 'If you're a parent, you understand'
The little boy just turned six over the weekend.
"We're all trying to bring Sam home," said Tonya. "It was his birthday Saturday and it should have been the happiest day of his life."
Tonya said she saw and held Sam for the last time on May 2 while he and his cousins visited her house. She added that she last spoke with the 6-year-old a week and a half or so ago.
Houston police said they're working through conflicting information surrounding Sam's last whereabouts.
Theresa Balboa, who is Sam's father's girlfriend, said she last saw the child last Thursday morning in the 8800 block of McAvoy Drive in southwest Houston.
"I was going to take Sam to school when his mother showed up with the police officer, or who I was under the impression to be a police officer, and they demanded me to release Sam," explained Balboa on Monday.
Balboa said she handed the young boy to the mom because the parents are in a custody battle. However, Satterwhite said investigators have not been able to verify that and, in fact, Sam may have gone missing weeks ago.
Tuesday night, the attorney for Sam's mom, Sarah Olson, said she has actually not seen her son in almost a year.
"Our client has primary custody, but our client has been denied access for the child for many months," said Sarah's attorney Marco Gonzalez, the co-owner of Gonzalez Law Group. "Our client has not had any access to young Samuel in many, many months."
When asked about the story of Sarah taking a police officer to get Sam, Gonzalez said "that is completely untrue."
The last time anyone outside of his family saw Sam was at Holbrook Elementary in Cy-Fair ISD on Friday, April 30, according to police. The last day of school is June 3.
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