Prince George's County police on Wednesday identified 22-year-old Justin DeSha-Overcash as the University of Maryland student who was shot to death Tuesday morning just minutes from the College Park campus in a drug-related robbery. "It appears that he was involved in the distribution of marijuana," said police spokesman Maj. Andy Ellis. "Whether it was large-scale or small-scale, I can't tell you."

Ellis said the amount of pot found at the house "was much more" than what someone possessing it for just themselves would have. A digital scale and packaging materials were also found, he said.

Authorities say a man wearing a ski mask fled DeSha-Overcash's home around 11:30 a.m. Tuesday. No arrests have been made, though Ellis said "the investigation is very active."

"It is very tragic," he said.

The county has seen 13 homicides since the beginning of the year. Medical examiners ruled a death that occurred late last week a homicide on Wednesday, according to police spokesman Evan Baxter. Alitha Mae Jenkins, 51, was found dead Friday in Capitol Heights. Authorities did not release the cause of death.

Almost all the victims have been black, though DeSha-Overcash is white.

Police say the homicides do not appear to be random. Six of the homicides probably involved drugs, Ellis said, and the others are likely the result of personal disputes or gang connections. The latest fatality was Clyde Antwone Rosevelt Howard, 30, who police say was shot by the resident of a New Carrollton residence while trying to break into the home late Tuesday night.

On Wednesday, there were no signs that a crime had occurred at the house DeSha-Overcash lived on 38th Avenue in College Park, near a Presbyterian church and Jehovah's Witness house of worship. A neighbor who lives across the street, 21-year-old Ivan Acuna, said four or five guys live in the house where DeSha-Overcash was killed, but he doesn't know any of them. Most of the people who live on the street are University of Maryland students, he said.

One neighbor, who did not want to be named, said there were lots of parties at the two-story brick and blue-paneled house.

Ross Leonhart, 21, another student who lives one street over, said the incident doesn't scare him and his friends. "We all feel safe. We don't feel like people are just walking into houses shooting people. We feel there must have been something behind it."

According to court records, DeSha-Overcash had two traffic violations: one in Baltimore County for failure to show his auto registration when asked in 2009, and failure to stop for a pedestrian in a crosswalk on the University of Maryland campus, also in 2009.

Kara Sarvey, a hometown friend who met DeSha-Overcash in ninth grade and dated him for several years, said he was an avid University of North Carolina fan who played football in high school and was majoring in both physics and astronomy in college.

"He was looking to go to grad school for something involving music," she said.