A man believed to be linked to a 1999 sexual assault in Maryland involving a cattle prod was mistakenly released from prison due to a clerical error, the Baltimore Sun reported Thursday.

Ronald Lee Moore, 40, walked out of the Baltimore City Correctional Center last month after doing time for assault and burglary. What corrections officials did not know was that Moore was to remain jailed after being linked through DNA to the separate sexual assault case, the Sun reported. Corrections officials did not become aware of the mistake until Friday.

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On Oct. 23, 1999, a masked man forced his way into an apartment and told the woman living there that he would kill her baby if she made any noise. He then forced her to perform a sex act, shocked her with a cattle prod and punched her "numerous times" in the head before fleeing, according to records obtained by the Sun.

There were no leads in the case until DNA taken from the crime scene was linked to Moore, a former crack addict who has spent only four years of his adult life out of prison.

Guards twice failed to bring him from the prison for hearings on the sexual assault charges, the Sun reported.