File / WFAA-TV

A constable's car was torched on March 24.

DALLAS — Three teens have pleaded guilty to a string of car arsons in southern Dallas, fire officials said Thursday.

Hearings ended Tuesday for three boys who have been sentenced to the Texas Youth Commission, Dallas Fire-Rescue said. The three admitted to their involvement in a number of vehicle fires earlier this year.

A fourth suspect is in custody and awaiting trial.

A string of arsons that began in February lasted for weeks and resulted in more than 20 vehicle fires, including the torching of a Dallas County deputy constable's marked car in Oak Cliff.

In April, investigators caught four teens, ages 13 to 16, setting an undercover vehicle on fire. Dallas Fire-Rescue said that since the arrests were made, the number of vehicle fires in the area have decreased dramatically.