The Florida man accused of murdering a 20-year-old woman and the 2-year-old son they shared had his first court appearance Saturday.

Thomas Mosley, 21, is being charged with two counts of first-degree murder, according to online records, after the body of 2-year-old Taylen Mosley was found in an alligator's mouth at a lake 15 minutes from the apartment his mother, Pashun Jeffrey, was found stabbed to death in.

"Pinellas Circuit Judge Patrice Moore struggled to communicate at times with Mosley, who called in on a phone from St. Anthony's hospital, where he remains in police custody while being treated for injuries. He didn't make an official plea, and Moore believed he was on medication," FOX 13 reports. 

More details about what happened on March 29, the day the mother and son were last seen alive, came to light during the arraignment.

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Thomas Mosley mugshot

Thomas Mosley, 21, charged with two counts of first-degree murder. (Pinellas County Sheriff's Office)

"It is alleged that the victim's family visited the victim's home at approximately 4:30 p.m. for the defendant's birthday party," Judge Moore read. "The victim's family left around 5:15, and the only person remaining in the home were the victim and her 2-year-old son." 

Phone records showed Jeffrey's device left the area of her apartment around 8:42 p.m. and headed to Lake Maggiore, where Taylen's body was later found on Friday before Mosley showed up at his mother's house with lacerations to his arms shortly after 9 p.m. He later checked himself into St. Anthony's, according to the criminal complaint.

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Dell Holmes Park

The park where Taylen Mosley's body was found in an alligator's mouth off Lake Maggiore in St. Petersburg, Florida.    (FOX 13 Tampa Bay)

On Thursday, Jeffrey's mother contacted the apartment complex property manager after not hearing from her daughter. When maintenance arrived to check on her, they reportedly walked into a gruesome scene where she was found with over 100 stab wounds and evidence that allegedly links Mosley to her murder.

"A bloody fingerprint on a cleaning bottle placed under a bed was identified as the defendant's," Moore explained. "A bloody shoe print with a Gucci emblem was located on the bathroom floor where the victim was found. The victim's brother said the defendant was wearing a pair of Gucci slides when he arrived at his mother's home."

Mosley and Jeffrey

Authorities said they found the body of 2-year-old son Taylen Mosley, left, late Friday. His mother, 20-year-old Pashun Jeffrey, right, was found murdered on Thursday in St. Petersburg, Florida, police say.

Mosley will be held at the Pinellas County Jail without bond once released from the hospital, according to FOX 13. 

The pair had just moved into the apartment complex about a month ago.

The St. Petersburg Police outside the apartment complex

Taylen's mother Pashun Jeffrey was found murdered in her apartment. (St. Petersburg Police Department)

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Police have not revealed how the toddler was killed or whether the alligator had played a role in that. The medical examiner will determine his cause of death.

Fox News' Juila Musto and the Associated Press contributed to this report.