ALIQUIPPA (KDKA) — The young man who has been missing since the fatal shooting of a 16-year-old boy last week in Beaver County has also been found dead.

Police found the body of 18-year-old Dane Mathesius in the backyard of a home in the 1100 block of Irwin Street in Aliquippa Tuesday afternoon. It’s not clear how long he had been there.

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Authorities had been searching for him since last Thursday night when the Honda Civic he was driving was shot up just a short distance away on Wade Street.

Mathesius, police said, ran from the scene after the shooting.

Lisa Washington’s Report:

The body of 16-year-old William “Cade” Booher was in Mathesius’ car. Booher was shot multiple times. Police described the incident as a “drug deal gone awry.”

Aliquippa Police Detective Capt. Ryan Pudik told reporters, “We did determine that it is the body of Dane Mathesius. [This case is] a double homicide. Obviously, we’re awaiting the official results of an autopsy.”

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A 13-year-old passenger in the car with Mathesius and Booher told investigators he and the other two teenagers came to Aliquippa to sell some marijuana.

Police are continuing their search for the alleged gunman they say was responsible for the incident. He’s identified as 17-year-old Lawrence Reddick Jr., nicknamed “Pooh Rat.” He’s an Aliquippa High School student.

The witness said when Reddick got in Mathesius’ car to buy the marijuana, Reddick pulled out a gun and demanded money and drugs, and then he fired his gun.

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Two teenagers who were with Reddick the night of the robbery and shooting were taken into custody Monday night.

Ronald Harvey Foster Jr. and Deontae Jones, both 17 and from Aliquippa, are members of the Aliquippa Hugh School football team. They are being charged as adults with homicide, conspiracy and robbery.

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Capt. Pudik said, “Mr. Reddick is currently still actively being sought. He is wanted and believed to be armed and dangerous.”