The Delaware County DA said the victim was murdered as he was "walking down the street in his own neighborhood."
UPPER DARBY, Pennsylvania (WPVI) -- An arrest has been made in what police are now calling the random murder of a 15-year-old in Upper Darby, Pennsylvania last spring.
The same suspect is also suspected of stabbing a pregnant woman during a carjacking just two months before.
Marson Weh, 24, was charged with first-degree murder in the death of Michael Garr, a 10th grader in the Upper Darby School District.
District Attorney Jack Stollsteimer said Garr was minding his own business when he was murdered.
"A juvenile who was doing nothing more than any juvenile should be able to do anywhere in America: just walking down the street in his own neighborhood," Stollsteimer said. "He was stabbed and killed at random."
Stollsteimer went on to say this case is "one of the most heinous crimes I've seen in my time as district attorney."
The stabbing happened on the 200 block of Bridge Street around 9:47 p.m. on April 21, 2023.
Police say during the investigation they were able to locate an image of a man running from the scene and who was last seen heading toward the 100 block of Willowbrook Avenue in Clifton Heights.
Upper Darby Police Superintendent Timothy Bernhardt said undercover officers were working in that area and 11 days after Garr's murder, Weh was spotted coming out of a home on the 100 block of Willowbrook Avenue wearing the same clothing worn on the night of Garr's murder.
Weh was taken into custody but police say he refused to cooperate with investigators. Weh was then extradited to Ohio to face charges related to assault and vehicle theft. He has since pled guilty to those charges and was sentenced to nine-and-a-half years in prison.
Since Weh was in custody in Ohio, Stollsteimer said local authorities used the time to gather additional evidence in this case.
"We only get one chance to charge somebody with first-degree murder and we're not going to do that until we're sure," he said.
A search warrant executed on the Willowbrook Avenue home led police to a number of items that were worn and used the night of Garr's murder, Bernhardt said.
Then, in December, police say evidence processed by the Philadelphia Crime Lab connected Weh to both Garr's murder, along with the Feb. 7, 2023 stabbing and carjacking of a pregnant woman on Bishop Avenue in Upper Darby.
Police say the vehicle stolen in that carjacking was later found in the same area of Clifton Heights where Weh would later be arrested.
Weh will be coming back to Pennsylvania to face charges here, Bernhardt said.
Over the summer, family members told Action News they were launching a non-profit to honor his memory.
It will be used to help children achieve their goal of higher education in fields like sports broadcasting, which was Garr's life-long dream.