Seth Rich came to D.C. to pursue a career in politics and most recently worked at the Democratic National Committee. Rich was shot dead in his Northwest Washington neighborhood on July 10. Here is what's known about the murder. (Claritza Jimenez/The Washington Post)

Seth Rich made such an impression as a teenage intern in Nebraska that a U.S. Senate campaign hired him before he completed high school. A young man who dreamed politics, he headed to Capitol Hill after college.

As a staffer at the Democratic National Committee, Rich worked tirelessly on a project to help voters easily find their polling places. But he was lighthearted, too, sometimes pulling on a sweatshirt adorned with a picture of a panda, his favorite animal, just to make co-workers laugh.

Early Sunday morning, the 27-year-old was shot to death in a crime that has shaken not only his family, colleagues and friends, but also many in his Bloomingdale neighborhood of Northwest. Police said they have no suspects, witnesses or motive, though they are looking at whether Rich could have been slain in an attempted robbery.

Rich was found shot several times, at least once in the back, about 4:20 a.m., after police were alerted by sensors that detect the sound of gunfire. ShotSpotter sensors drew officers to Flagler Place and W Street, a block from a townhouse Rich moved into two years ago with several roommates.

Rich’s father, Joel I. Rich, 68, said he believes that his son was killed after resisting a robbery in which the assailant got nothing — the victim’s watch, wallet and credit cards were not taken.

Police are hoping to locate surveillance video and are urging people to come forward with information.

The elder Rich said that he didn’t know where his son had been before he was shot but that he thinks that he was walking home and talking on the phone with a woman he dated. Rich wasn’t sure whether they were talking when the attack occurred.

“He wanted to make a difference,” Joel Rich said of the younger of his two sons. “Politics was in his blood.” He called his son’s killing “a waste.”

In his final posting on Facebook, Seth Rich addressed a nation racked by shootings by and of police: “Too much pain to process. We have to be better and defend each other. . . . A life is exponentially valuable. I have family and friends on both sides of the law. Please, stop killing each other.”

Acting D.C. Police Capt. Anthony Haythe, head of the homicide unit, said detectives are examining several recent robberies in the area to determine whether any can be linked. There were two robberies in the city in the hour preceding the shooting, both more than one mile away. Three people were robbed at gunpoint and another person was carjacked within four days in June on Flagler Place, near where Rich was shot. Police report 20 armed holdups in Bloomingdale so far this year, compared with eight at this time in 2015.

Bloomingdale, a rectangular-shaped community split by Rhode Island Avenue, has made a turnaround over the past several years, emerging from a neighborhood hit hard by crime into one attracting new homeowners. Construction work to alleviate persistent flooding has resulted in the shutdown of numerous streets and turned many others into dead-ends, which some residents say has created a poorly lit labyrinth that traps people and benefits robbers.

City officials promised to work closer with police to improve lighting and visibility by removing construction tarps that block views of the streets. Teri Janine Quinn, who heads the Bloomingdale Civic Association, called the killing and recent holdups “terrifying.” She added: “No one wants to be able to feel they can’t go home at night. Nobody wants to hear that someone was murdered blocks from their home.”

Rich grew up in Omaha, living with his parents and older brother, and fell in love with politics at an early age. A senior in high school and in need of volunteer credits, a teacher brought him to the reelection campaign for former U.S. senator Ben Nelson (D-Neb). Marc Shultz, then one of Nelson’s campaign officials, quickly hired the young political protege.

“He was a great kid, but he also was the real deal,” Shultz said.

Rich enrolled at his hometown Creighton University, studying political science and public policy, and while a sophomore, worked on the U.S. Senate campaign for Nebraska businessman Scott Kleeb (D), who lost.

Kleeb said Rich was his field organizer, which he described as “the most unglorious part of campaigning. It’s the person who has to organize the people who sit behind the table to take your email so we can contact them afterward.” Kleeb said Rich made volunteers “feel valued.”

After graduating in 2011, Rich was quickly hired by a national polling company and moved to the District. Two years later, he went to the Democratic National Committee, where he worked on the development of a computer program that allows people to enter their names and have maps drawn to their polling places. It required data culled from every voter precinct in the country. The DNC’s chairwoman, Rep. Debbie Wasserman Schultz (Fla.), said in a statement that Rich worked “to protect the most sacred right we share as Americans — the right to vote.”

Rich moved to First Street two years ago. He didn’t have a car, and he walked or bicycled to work, with only ice stopping him. He wore a panda suit whenever he could — his mother said he simply found them “cute and adorable” — and for July 4 he dressed from shoe to shirt in the garments of the Stars and Stripes. In one photo, he’s holding a beer wrapped in a American-flag cooler.

His father said Rich volunteered at the Humane Society and was first to help colleagues who were going on vacation and needed a dog sitter. He recently ran into Shultz, who hired him on the Nelson campaign, while heading to lunch on Capitol Hill. The two reminisced about Nebraska politics. They also sometimes found each other at Lounge 201, a bar on Capitol Hill, to take in University of Nebraska football games.

James Green, the field director on Kleeb’s Senate campaign and now an accounts executive, also became friends with Rich, who he described as a “proud, Nebraska Democrat. Lover of Husker football and Creighton Bluejays basketball.”

“In this business, people cycle in and out, but not him,” said Green, who had planned to see Rich and other friends soon over drinks. “He was going to be a rising star. It’s just tragic that his life was cut so short. Unfortunately I couldn’t say goodbye to my friend.”

Jennifer Jenkins, Abby Phillip and Perry Stein contributed to this report.