ALLENTOWN, Pa. -

Allentown police have arrested three teenagers -- one a juvenile -- in connection with a deadly shooting.

Lionel Blackledge, 27, was found dead in the driver's seat of a car Sunday afternoon in the 100 block of East Cumberland Street.

Police were responding to a call of gunshots fired, when they arrived they found Blackledge with gunshot wounds to the head and neck around 4:30 p.m.

Following a 24-hour plus investigation, police arrested 19-year-old Charles Demai Washington and charged him with robbery and criminal homicide, among other offenses.

Washington was arrested after police and SWAT team members put the area of South Carlisle St. near Hanover Ave. under lock down Monday morning.

Washington was seen leaving a home on Carlisle St. escorted by officers. According to the district attorney, Washington does not have a known residence.

Investigators say a 14-year-old juvenile identified as 'JR' was also detained and faces various charges, including possession of a firearm and robbery.

Nineteen-year-old Sahir Quasim-Mark Terry was arrested early Monday morning at his home on South Carldon St.

Terry is charged with obstructing the law and hindering apprehension.

According to the district attorney, Blackledge was killed during the commission of a robbery.

Blackledge was allegedly trying to sell marijuana to Washington and the 14-year-old.

Terry's connection to the incident remains unclear.