There is no credible evidence or official documentation supporting the claim that there were at least 5,000 documented cases of sexual abuse of migrant children by ICE and Border Patrol under the Trump administration.
Under the previous Trump administration there were at least 5000 documented cases of ICE and Border Patrol sexually abusing migrant children.

FactVerify
Source: factverify.com
Key Evidence
PBS News reports hundreds of immigrant sexual abuse allegations at ICE facilities but does not support thousands of documented cases.
pbs.orgpbs.orgHundreds of immigrants have reported sexual abuse at ICE facilities. Most cases...
Official ICE statistics do not list or confirm 5,000 documented cases of sexual abuse involving migrant children.
ice.govice.govICE Enforcement and Removal Operations Statistics
The ACLU discusses legal responsibility but does not verify such a high number of incidents.
What the Evidence Shows
The claim asserts a specific and large number, 5,000 documented cases, of sexual abuse by ICE and Border Patrol agents against migrant children during the Trump administration. Official statistics from ICE and DHS do not report such a figure, nor do reputable investigations or news reports corroborate this number.ice.govice.govICE Enforcement and Removal Operations Statistics
pbs.orgpbs.orgHundreds of immigrants have reported sexual abuse at ICE facilities. Most cases... While there have been documented instances and allegations of sexual abuse and misconduct in immigration detention facilities, these are reported in the hundreds rather than thousands, and many cases remain uninvestigated or unresolved.
pbs.orgpbs.orgHundreds of immigrants have reported sexual abuse at ICE facilities. Most cases...
The American Civil Liberties Union highlights legal accountability issues but does not confirm such a high volume of documented cases. Additionally, media coverage and government reports focus on systemic issues and individual cases rather than a quantified total anywhere near 5,000. The claim conflates allegations and reports with confirmed, documented cases, which is a significant distinction.
No credible source provides evidence for the scale claimed. Therefore, the claim is factually inaccurate and misleading in its numerical assertion.