Explaining the discrepancy, Mr. Mathis said, “They’re telling me they asked her those questions two different times, that she gave different answers the second time.”

The intake forms also said that Ms. Bland was taking an antiseizure medication, Keppra, for epilepsy. The drug comes with a warning label approved by the Food and Drug Administration that includes a long list of possible side effects, including depression, aggressive behavior and thoughts of suicide. It was unclear whether she had access to the drug while in jail.

During a news conference illustrated with photographs of Ms. Bland’s corpse, Mr. Diepraam said her body carried abrasions on the back and lacerations on the wrists that could have been suffered during her arrest, or later by handcuffs. But there was no sign of serious injuries, he said, and no cuts or bruises that might suggest she had fought in her jail cell to keep someone from killing her.

Examiners also found scars and scabs from about 30 cuts on Ms. Bland’s left forearm, which they said had probably occurred two to four weeks ago. Prosecutors declined to say definitively what caused them, but “in multiple instances I have seen, those injuries, they are consistent with self-inflicted wounds,” Mr. Diepraam said.

An initial toxicology test also indicated that Ms. Bland had recently smoked or eaten marijuana, Mr. Diepraam said. He noted that because traces of marijuana leave the body quickly, she had to have consumed it not long before she died, and he said it could have been used in the jail.

Inmates near Ms. Bland’s cell did not smell marijuana smoke, and the cell contained no evidence of the drug, he said. He raised the possibility that she could have ingested it right before the traffic stop to avoid being arrested for drug possession. Explaining why the information was relevant, he said, “It is a mood-altering substance and a mood amplifier.”