To substantiate claims in a report means to:

Substantiating claims in a report involves providing proof to support the assertions made within the document. This proof can come in various forms, including witness statements, physical evidence, or documentation. By including substantiated claims, the report gains credibility and reliability, demonstrating that the information presented is based on verifiable facts rather than mere opinion or speculation. This is crucial in police report writing, as law enforcement documents often serve as foundational evidence in legal proceedings, requiring a high standard for accuracy and integrity. The emphasis on corroborating details helps ensure that the report can withstand scrutiny and be used effectively in investigations or court situations.