A Maryland man is facing life in prison without the possibility of parole after a jury found him guilty in the 2017 deaths of his 6-year-old sister and two young cousins.

The Office of State Attorney Aisha Braveboy said jurors deliberated for about two hours in a Prince George's County court on Thursday before convicting Antonio Shareek Williams of murder and three first-degree child abuse charges. 

Braveboy's office said Williams' sentencing is set for May 19.

Williams, 30, was accused in the fatal stabbings of his sister Nadira Withers and cousins Ajayah DeCree, 6, and Ariana DeCree, 9. Investigators said he had confessed to the crimes shortly after he was arrested.

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Antonio Shareek Williams mugshot

Antonio Shareek Williams, now 30, was convicted Thursday in the 2017 stabbing deaths of his little sister and two young cousins. (Prince County George's Police Department)

"I’m just happy these three innocent lives got the justice they deserve," Kenneth Withers, the father of Nadira Withers, said after the verdict, according to the Associated Press.

All three girls were solely in Williams' care the night they died as his mother was working an overnight nursing shift, according to arrest reports. The DeCree sisters were visiting from New Jersey and were the daughters of the mother's cousin.

Prosecutors argued that Williams was annoyed at the girls for making noise and running up and down the stairs at the home. At trial, they argued that he grabbed a knife from the kitchen, went to the bedroom the girls were in, stabbed all three multiple times and then put the knife away.

His mother found the girls' bodies the next morning when she returned home from work. They were pronounced dead at the house.

Local news outlets reported Williams' 2-year-old sibling was also in the home at the time, but was not harmed.

Kenneth Withers and Nadira Withers

Kenneth Withers and his daughter Nadira Withers pose for a picture before she was murdered in August 2017. (Live For Nadira - GoFundMe)

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Prosecutors said Williams cleaned up the scene and the knife, but there was enough DNA evidence to link him to the crimes.

He was arrested hours after the bodies were discovered.

"They should be enjoying their lives, pursuing their dreams, yet they were killed by a family member," Braveboy said of the little girls.

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Jonathan Church, a prosecutor who helped take the case to trial, said it took a long time to process because of turnover within Braveboy's office, a change in defense attorneys and pandemic-related delays, the AP reported.

The Associated Press contributed to this report.